HEYDAY
flower, prime, peak, heyday, bloom, blossom, efflorescence, flush
(noun) the period of greatest prosperity or productivity
Source: WordNet® 3.1
Etymology
Noun
heyday (plural heydays)
A period of success, popularity, or power; prime.
(archaic) An exultation of the spirits; gaiety; frolic.
Synonyms
• day in the sun
• golden age
• golden years
Interjection
heyday
A lively greeting.
(obsolete) An expression of frolic and exultation, and sometimes of wonder.
Synonyms
• (greeting): See Thesaurus:hello
• (expression of wonder): See Thesaurus:wow
Source: Wiktionary
Hey"day`, interj. Etym: [Cf. G. heida, or hei da, D. hei daar. Cf.
Hey, and There.]
Definition: An expression of frolic and exultation, and sometimes of
wonder. B. Jonson.
Hey"day`, n. Etym: [Prob. for. high day. See High, and Day.]
Definition: The time of triumph and exultation; hence, joy, high spirits,
frolicsomeness; wildness.
The heyday in the blood is tame. Shak.
In the heyday of their victories. J. H. Newman.
Source: Webster’s Unabridged Dictionary 1913 Edition