See prime in Webster's New World College Dictionary
adjective
first in time; original; primitive; primary
first in rank or authority; chief: the prime minister
first in importance or value; principal; main: a prime advantage
first in quality; of the highest excellence: prime beef
from which others are derived; fundamental; basic
Math.
of or being a prime number
having no factor in common except 1: 9 and 16 are prime to each other
noun
R.C.Ch. a part of the Divine Office orig. assigned to the first hour of daylight (in the Liturgy of the Hours, both Lauds and Prime have been replaced by Morning Prayer)
the first hour of the daylight, conventionally taken to begin about 6 a.m.
the earliest part of something; beginning
springtime
the springtime of life; youth
the best, most vigorous, or most fully mature period or stage of a person or thing: a soprano in her prime
the best part of anything
the best of several or many; pick; cream
a symbol () used
to distinguish between different values of the same variable
to distinguish a letter, number, or other character from another of the same kind, as A
for certain units of measure, as feet or minutes of arc