prime

American  

[prahym] / praɪm /

adjective

1. of the first importance; demanding the fullest consideration.

   a prime requisite.

   Synonyms:

   primary

2. of the greatest relevance or significance.

   a prime example.

3. of the highest eminence or rank.

   the prime authority on Chaucer.

4. of the greatest commercial value.

   prime building lots.

5. first-rate.

   This ale is prime!

6. (of meat, especially of beef ) noting or pertaining to the first grade or best quality.

   prime ribs of beef.

7. first in order of time, existence, or development; earliest; primitive.

8. basic; fundamental.

   the prime axioms of his philosophy.

9. Mathematics. (of any two or more numbers) having no common divisor except unity.

   The number 2 is prime to 9.

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noun

• primes
  plural

1. the most flourishing stage or state.

2. the time of early manhood or womanhood.

   the prime of youth.

3. the period or state of greatest perfection or vigor of human life.

   a man in his prime.

4. the choicest or best part of anything.

5. (especially in the grading of U.S. beef ) a grade, classification, or designation indicating the highest or most desirable quality.

6. the beginning or earliest stage of any period.

7. the spring of the year.

8. the first hour or period of the day, after sunrise.

9. Banking. prime rate.

10. Ecclesiastical. the second of the seven canonical hours or the service for it, originally fixed for the first hour of the day.

11. Mathematics.

    1. prime number.

    2. one of the equal parts into which a unit is primarily divided.

    3. the mark (′) indicating such a division.

       a, a′.

12. Fencing. the first of eight defensive positions.

13. Music.

    1. unison.

    2. (in a scale) the tonic or keynote.

14. Linguistics. any basic, indivisible unit used in linguistic analysis.

15. Metallurgy. a piece of tin plate free from visible defects.

verb (used with object)

• primes,
  present (3rd person singular)
• primed,
  past participle,  past
• priming
  present participle

1. to prepare or make ready for a particular purpose or operation.

2. to supply (a firearm) with powder for communicating fire to a charge.

3. to lay a train of powder to (a charge, mine, etc.).

4. to pour or admit liquid into (a pump) to expel air and prepare for action.

5. to put fuel into (a carburetor) before starting an engine, in order to insure a sufficiently rich mixture at the start.

6. to cover (a surface) with a preparatory coat or color, as in painting.

7. to supply or equip with information, words, etc., for use.

   The politician was primed by his aides for the press conference.

8. to harvest the bottom leaves from (a tobacco plant).

verb (used without object)

• primes,
  present (3rd person singular)
• primed,
  past participle,  past
• priming
  present participle

1. (of a boiler) to deliver or discharge steam containing an excessive amount of water.

2. to harvest the bottom leaves from a tobacco plant.

prime British  

/ praɪm /

adjective

1. (prenominal) first in quality or value; first-rate

2. (prenominal) fundamental; original

3. (prenominal) first in importance, authority, etc; chief

4. maths

   1. having no factors except itself or one

      x² + x + 3 is a prime polynomial

   2. (foll by to) having no common factors (with)

      20 is prime to 21

5. finance having the best credit rating

   prime investments

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noun

1. the time when a thing is at its best

2. a period of power, vigour, etc, usually following youth (esp in the phrase the prime of life )

3. the beginning of something, such as the spring

4. maths short for prime number

5. linguistics a semantically indivisible element; minimal component of the sense of a word

6. music

   1. unison

   2. the tonic of a scale

7. RC Church the second of the seven canonical hours of the divine office, originally fixed for the first hour of the day, at sunrise

8. the first of eight basic positions from which a parry or attack can be made in fencing

verb

1. to prepare (something); make ready

2. (tr) to apply a primer, such as paint or size, to (a surface)

3. (tr) to fill (a pump) with its working fluid before starting, in order to improve the sealing of the pump elements and to expel air from it before starting

4. (tr) to increase the quantity of fuel in the float chamber of (a carburettor) in order to facilitate the starting of an engine

5. (tr) to insert a primer into (a gun, mine, charge, etc) preparatory to detonation or firing

6. (intr) (of a steam engine or boiler) to operate with or produce steam mixed with large amounts of water

7. (tr) to provide with facts, information, etc, beforehand; brief

prime Idioms  

More idioms and phrases containing prime

• past one's prime

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Usage

What is a basic definition of prime? The word prime is used in mathematics to refer to a prime number, a number that can only be divided by itself or the number 1 to equal a whole number. The word prime can be used to describe something as the most important or most relevant among other similar things, like a prime example or a prime suspect. The word prime has many other senses as an adjective, noun, and verb. A number is considered to be a prime number if it can only be divided by itself and 1 to get a whole number, meaning there is no fractional or decimal remainder.

• Real-life example: The number 7 is a prime number. It can be divided by itself to equal 1 or by 1 to equal 7. Dividing 7 by any other number will not result in a whole number. For example, 7 divided by 2 is 3. 5 (3 ½). Numbers that aren’t prime are called composite numbers. The number 6, for example, is a composite number because it can be divided by 3 to equal 2, which is a whole number. The numbers 3, 5, 7, 11, 13, and 17 are examples of prime numbers.
• Used in a sentence: The number 51 is not a prime number because it can be divided by 3 to get 17.

The word prime is also used as an adjective to describe something as the most important among other things. The adjectives primary and chief are close synonyms.

• Real-life example: If a high school student’s grades are the prime factor that a college considers when reviewing their application, this means it is the most important thing being considered. Your mom might say that you lying to her is the prime reason she is grounding you. This means that the lie was the most important reason and the fact that you didn’t clean your room or walk the dog are less important reasons.
• Used in a sentence: Studying before taking tests is the prime factor that will determine if you pass or fail a class.

The word prime is also used as an adjective to describe something as the most relevant or significant.

• Real-life example: Your teacher might say that Bill Gates is a prime example of how learning about computers can lead to success in life, meaning he is the best example.
• Used in a sentence: The fact that my sister gave me $100 with no questions asked is a prime example of her generosity.

Synonym Usage

Prime, primeval, primitive have reference to that which is first. Prime means first in numerical order or order of development: prime meridian; prime cause. Primeval means belonging to the first or earliest ages: the primeval forest. Primitive suggests the characteristics of the origins or early stages of a development, and hence implies the simplicity of original things: primitive tribes, conditions, ornaments, customs, tools.

Other Word Forms

Derived Forms

• primeness
  noun
• reprime
  verb (used with object)
• nonprime
  adjective
• self-primed
  adjective
• unprimed
  adjective
• well-primed
  adjective
• primely
  adverb

Inflected Forms

Nouns

• primes
  plural

Participles

• priming
  present
• primed
  past

Conjugated Forms

Present

• prime
  simple
• primes
  simple
• have primed
  perfect
• has primed
  perfect
• am priming
  progressive
• are priming
  progressive
• is priming
  progressive
• have been priming
  perfect progressive
• has been priming
  perfect progressive

Past

• primed
  simple
• had primed
  perfect
• was priming
  progressive
• were priming
  progressive
• had been priming
  perfect progressive

Future

• will prime
  simple
• will have primed
  perfect
• will be priming
  progressive
• will have been priming
  perfect progressive

Etymology

Origin of prime

First recorded before 1000; 1910–15 prime for def. 5; (adjective) Middle English (from Old French prim ), from Latin prīmus first (superlative corresponding to prior prior ¹ ); (noun) in part derivative of the adjective; in part continuing Middle English prim(e) “first canonical hour,” Old English prim, from Latin prīma (hōra) “first (hour)”; (verb) apparently derivative of the adjective

Explanation

If something is in its prime, it is at its best. The same goes for a person. If you are young and healthy and in the prime of your life, you are ready to take on the world. Prime often means "main." The prime reason you go to concerts is to see your favorite groups perform. If your mother is angry that you came home late, tell her that this is a prime example of why you need a cell phone — so you can call her. It can also mean "of the highest quality" as in prime beef or flowers. As a verb, prime means to get ready. Hopefully you've primed yourself for your exams. Prime the pump and start the engine!

Example Sentences

See Examples For:

prime primes primed priming

This is a sensitive area for the prime minister.

From BBC ● Oct. 8, 2026

He is fanatical about keeping himself in prime physical condition, with a regimen that blends new-age techniques and the wisdom of the fjords.

From The Wall Street Journal ● Oct. 8, 2026

The country's former deputy prime minister is on the run.

From Barron's ● Oct. 8, 2026

The seat became vacant after former prime minister Sir Keir Starmer announced he was standing down to focus on a role in international affairs.

From BBC ● Oct. 8, 2026

"The evil Dr. Loofah is climbing into the helicopter! He has the prime minister's cat and puppy!"

From "Dog Squad" by Chris Grabenstein

Its shares now trade at less than 16 times forward free cash flow, by far the cheapest in and a third lower than the basket of defense primes.

From The Wall Street Journal ● Aug. 28, 2026

The Riemann Hypothesis, often considered the most difficult and important problem in all of mathematics, would serve as a Rosetta stone revealing the secrets of the primes.

From Slate ● Jun. 22, 2026

A bout that should have happened in both men's primes, it now lingers as boxing's great what-if - but it appears it may finally be made a reality.

From BBC ● Apr. 11, 2026

Four of the five primes fetch roughly 26 times expected earnings on average, near their historic highs.

From The Wall Street Journal ● Mar. 17, 2026

He stayed up at night, trying to figure out what it is in the delivery of a tennis serve that primes his judgment.

From "Blink" by Malcolm Gladwell

A two-time All-Star, he’s primed to lead a promising backcourt alongside 19-year-old rookie Keaton Wagler, the Clippers’ No. 5 pick in the 2026 draft.

From Los Angeles Times ● Sep. 28, 2026

"What we found in patient samples was that intestinal cells are primed to die. Even in patients with essentially no symptoms, there's still this persistent problem sitting there."

From Science Daily ● Sep. 20, 2026

Indonesian villager Octavius wades through the forest in rubber boots and tattered joggers, ears pricked, eyes peeled, a telephoto lens on his phone primed to capture orangutans, monkeys or birds.

From Barron's ● Sep. 17, 2026

Joe Bradshaw: The last time the Super Bowl was at SoFi Stadium in 2022, the Rams won on home territory and they look primed to repeat next February.

From BBC ● Sep. 8, 2026

When you took that sentence-completion test, you didn’t know that you were being primed to think “old.”

From "Blink" by Malcolm Gladwell

Nasdaq is changing its procedures to put SpaceX in funds based on it and priming the pump to do the same with Anthropic and OpenAI, which have historically burned through cash.

From Slate ● Jun. 5, 2026

Their regular season consists of priming pitchers for October, not padding their resumes for awards.

From Los Angeles Times ● Apr. 8, 2026

After years of priming us to expect speedy deliveries, the ever-growing e-commerce economy is weaning us off them—and no one seems to mind.

From The Wall Street Journal ● Mar. 7, 2026

As Barron’s wrote last November, the company has been priming investors for the loss of Apple’s sales for years, and it may already be factored into the stock price.

From Barron's ● Jan. 9, 2026

“I don’t like it either. God, I hate it! That woman is priming herself for a nervous breakdown. I just hope she doesn’t have it while I’m here.”

From "Kindred" by Octavia Butler

Related Words

• choice
• excellent
• first-class
• first-rate
• great
• high-quality
• outstanding
• primo
• superior
• top-notch
• very good
• wonderful