of the first importance; demanding the fullest consideration

a prime requisite.

of the greatest relevance or significance

a prime example.

of the highest eminence or rank

the prime authority on Chaucer.

of the greatest commercial value

prime building lots.

first-rate

This ale is prime!

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

prime ribs of beef.

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

basic; fundamental

the prime axioms of his philosophy.

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

The number 2 is prime to 9.

the most flourishing stage or state.

the time of early manhood or womanhood

the prime of youth.

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

a man in his prime.

the choicest or best part of anything.

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

the beginning or earliest stage of any period.

the spring of the year.

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

Banking . prime rate.

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

Mathematics .

prime number.

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

the mark () indicating such a division

a, a.

Fencing . the first of eight defensive positions.

Music .

unison ( def. 2 ) .

(in a scale) the tonic or keynote.

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

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

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

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

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

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

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

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

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

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

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

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

to harvest the bottom leaves from a tobacco plant.