expression, godan verb (-tsu)
wait for a ripe moment; bide one's time
Fixed expression meaning to wait until the time is right or conditions are favorable before acting. Often used in strategic or patient contexts.
See also: 機が熟す
彼は機が熟すのを待ってから、計画を実行に移した。
He waited for the right moment before putting his plan into action.
機が熟す means 'the time is ripe' or 'conditions are favorable'; 機が熟すのを待つ is the full phrase meaning 'to wait for that ripe moment'.
A set phrase combining 機 (opportunity, time), 熟す (to ripen, mature), and 待つ (to wait). The exact historical origin is uncertain, but it follows a common pattern of using ripening as a metaphor for the right timing.