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

A young Michel Rocard, later the prime minister of France, was among those who went to help.

From The Wall Street Journal ● Aug. 16, 2026

"These days, one of the roles of a prime minister is to act as a content creator," Buckley told AFP.

From Barron's ● Aug. 16, 2026

No 10: Full Confidence by Benjamin Brewis sees players take on the role of prime minister, making decisions through a wave of parliamentary scenarios and trying to remain in power for as long as possible.

From BBC ● Aug. 15, 2026

The paper also quotes the prime minister: "It's a moment of reflection, reflecting on how much things came to this".

From BBC ● Aug. 15, 2026

This is one of the prime examples of the need to avoid acting on the basis of common sense if you want to know how the world works.

From "The Scientists" by John Gribbin

That is encouraging new entrants to work with the primes through production partnerships, said Gruen.

From The Wall Street Journal ● May 1, 2026

Report B primes a “Why you can’t trust collagen research” story.

From Slate ● Apr. 17, 2026

Not everything points to a resounding victory for defense primes.

From The Wall Street Journal ● Mar. 17, 2026

While valuation and volatility differ from traditional primes, the software layer most closely resembles true subscription economy within defense budgets.

From MarketWatch ● Feb. 28, 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

With Skubal in the mix, the Dodgers are primed to go into October with a collection of pitchers that ranks among the greatest in history.

From The Wall Street Journal ● Aug. 2, 2026

The 6-foot-4 forward is primed to be the Bruins’ anchor in the paint.

From Los Angeles Times ● Jul. 16, 2026

"The course is primed for an amazing week. It's as linksy as links gets," 2014 champion Rory McIlroy told BBC Sport's Iain Carter.

From BBC ● Jul. 14, 2026

In an information environment already primed for suspicion of institutions, the director’s silence read as confirmation that something was being withheld.

From Salon ● Jul. 13, 2026

This was the gold rush for geeks, a special time in history, the Internet moment, and he was primed to take advantage of that, to stake his claim.

From "Geeks: How Two Lost Boys Rode the Internet Out of Idaho" by Jon Katz

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

While speaking to Earth via a video link on Thursday, mission specialist Koch mentioned there had been a slight "priming" issue with the toilet.

From BBC ● Apr. 5, 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

To see one of their own priming the opposition did something to the team’s morale that hours of practice could not over-come.

From "Stargirl" by Jerry Spinelli

Related Words

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