[singular] the time in your life when you are strongest or most successful a young woman in her prime He was barely 30 and in the prime of (his) life. These flowers are long past their prime. Word Originnoun Old English prīm (referring to a service of the Divine Office of the Western Church, said at the first hour of the day), from Latin prima (hora)
‘first (hour)’, reinforced in Middle English by Old French prime; the adjective dates from late Middle English, via Old French from Latin primus ‘first’.Extra examples I’m afraid he’s long past his prime. She was cut off in her prime, and never lived to see the poems published. When he wrote the symphony he was in the prime of his life. He was barely 30 and in the prime of (his) life when he had the accident. It was late August and the flowers were long past their prime. She was then a great artist in her prime.