Other forms: primes
In mathematics, a prime number is one divisible only by itself and one. Two, three, five, seven, eleven. One is not prime, which is a definition rather than an accident.
The everyday adjective means first in importance or quality: the prime reason, prime beef, a prime site. In Britain the Prime Minister is the head of government. Prime time is the evening hours when television audiences are largest. As a verb, to prime is to prepare something — prime a wall before painting, prime a pump — and to prime somebody is to brief them in advance. Note in your prime, meaning at your peak.
1adjectiveprimeOf a number, divisible only by itself and one.
“Seventeen is prime and fifteen is not.”
2adjectiveimportantMost important.
“That was the prime reason and nobody said it aloud.”
3adjectivequalityOf the best quality.
“It is a prime site and it will not stay empty.”
4nounperiodThe best period of somebody's life.
“He was well past his prime and still winning.”
Too few real examples of this word to estimate which sense is commonest.
prime is a quality of being first.
Latin primus meant first — the same root as primary, premier, prince and principal. Everything in the family is about being first, and a prime number is first in the sense of being indivisible: nothing comes before it.
Proto-Indo-European
*per- — beyond, before
Proto-Italic
*priisemos
Latin
prīmus — first
Old French
prime
Middle English
prime
English, today
prime
From Middle English prime, from Old French prime and its etymon, Latin prīmus (“first”), from earlier prīsmos < prīsemos < Proto-Italic priisemos, ultimately from Proto-Indo-European per- (“beyond, before”). a doublet of primo and primus. The noun sense "apostrophe-like symbol" originates from the fact that the symbol ′ was originally a superscript Roman numeral one.
Etymology from Wiktionary, CC BY-SA