the most active, thriving, or successful stage or period, esp of one's life
One's prime is elusive. You little girls, when you grow up, must be on the alert to recognise your prime at whatever time of your life it may occur — Muriel Spark
archaic or literary the earliest period; the dawn
= prime number
the symbol (‘) used in mathematics as a distinguishing mark, e.g. in denoting derivatives of a function, or as a symbol for feet or minutes
in fencing, the first of eight parrying positions
(often Prime) the second of the traditional daily services of the Roman Catholic Church canonical hours, orig fixed for 6 a.m
[Old English prīm, from Latin prima hora first hour]