[ prahym ]
See synonyms for: primeprimedprimerprimest on

  1. of the first importance; demanding the fullest consideration: a prime requisite.

  2. of the greatest relevance or significance: a prime example.

  1. of the highest eminence or rank: the prime authority on Chaucer.

  2. of the greatest commercial value: prime building lots.

  3. first-rate: This ale is prime!

  4. (of meat, especially of beef) noting or pertaining to the first grade or best quality: prime ribs of beef.

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

  6. basic; fundamental: the prime axioms of his philosophy.

  7. Mathematics. (of any two or more numbers) having no common divisor except unity: The number 2 is prime to 9.

  1. the most flourishing stage or state.

  2. the time of early manhood or womanhood: the prime of youth.

  1. the period or state of greatest perfection or vigor of human life: a man in his prime.

  2. the choicest or best part of anything.

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

  4. the beginning or earliest stage of any period.

  5. the spring of the year.

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

  7. Banking. prime rate.

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

  9. Mathematics.

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

    • the mark (′) indicating such a division: a, a′.

  10. Fencing. the first of eight defensive positions.

  11. Music.

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

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

verb (used with object),primed, prim·ing.
  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.

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

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

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

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

  5. to supply or equip with information, words, etc., for use: The politician was primed by his aides for the press conference.

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

verb (used without object),primed, prim·ing.
  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.

Origin of prime

First recorded before 1000; 1910–15 for def. 5; (adjective) Middle English (from Old French prim), from Latin prīmusfirst (superlative corresponding to priorprior1); (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

synonym study For prime

7. 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 words for prime

Other words from prime

  • primeness, noun
  • non·prime, adjective
  • re·prime, verb (used with object), re·primed, re·prim·ing.
  • self-primed, adjective
  • un·primed, adjective
  • well-primed, adjective

Words Nearby prime Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use prime in a sentence

British Dictionary definitions for prime


/ (praɪm) /

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

  2. (prenominal) fundamental; original

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

  2. maths

    • having no factors except itself or one: x² + x + 3 is a prime polynomial

    • (foll by to) having no common factors (with): 20 is prime to 21

  3. finance having the best credit rating: prime investments

  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)

  1. the beginning of something, such as the spring

  2. maths short for prime number

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

  4. music

    • unison

    • the tonic of a scale

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

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

  1. to prepare (something); make ready

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

  1. (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

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

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

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

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

Origin of prime

(adj) C14: from Latin prīmus first; (n) C13: from Latin prīma (hora) the first (hour); (vb) C16: of uncertain origin, probably connected with n

Derived forms of prime

  • primely, adverb
  • primeness, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with prime


In addition to the idioms beginning with prime

  • prime mover
  • prime of life
  • prime the pump

also see:

  • past one's prime

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.