(さいせいき)

さいせいき
noun
peak period, heyday, prime
1. peak period, heyday, prime, height
The period when something is at its most active, productive, or prosperous. Used for seasons, industries, careers, civilizations, and other things that have a high point.
(さくら)最盛期(さいせいき)四月(しがつ)だ。
The peak season for cherry blossoms is April.
あの歌手(かしゅ)(いま)最盛期(さいせいき)だ。
That singer is at the peak of their career right now.
ローマ帝国(ていこく)()世紀(せいき)ごろに最盛期(さいせいき)(むか)え、広大(こうだい)領土(りょうど)支配(しはい)していた。
The Roman Empire reached its peak around the 2nd century and controlled vast territory.

COMMON COLLOCATIONS:

  • 最盛期(さいせいき)(むか)える: to reach one's peak
  • 最盛期(さいせいき)()ぎる: to be past one's prime
  • 最盛期(さいせいき)にある: to be in one's prime
  • (さくら)最盛期(さいせいき): peak cherry blossom season

ETYMOLOGY:
(さい) (most) + (せい) (flourishing) + () (period) — the period of greatest flourishing.

CONTRAST:
最盛期(さいせいき) focuses on the peak of activity or prosperity. 全盛期(ぜんせいき) (golden age, heyday) is similar but often carries a stronger sense of past glory or looking back at a period that has ended.