expression, godan verb (-su)
miss a golden opportunity; let a chance slip by
Used when someone fails to take advantage of a favorable moment, often with a sense of regret.
彼は好機を逃して、昇進できなかった。
He missed a golden opportunity and couldn't get promoted.
好機を逃すな。
Don't let this chance slip by.
Similar meaning but 好機 emphasizes a particularly favorable or golden opportunity, while 機会 is a more general term for opportunity.
Compound of 好機 (good opportunity) + を (object marker) + 逃す (to miss, let escape).