雌伏 (しふく) uses the on'yomi readings. 雌 (し) means female, and 伏 (ふく) means to lie down/be prostrate. This idiom means to lie low, bide one's time, or remain in obscurity while preparing for a future opportunity, often implying a submissive or humble posture. Incorrect readings often mispronounce 雌 as じ (じふく).

雌伏（しふく）は、雌（し）と伏（ふく）の音読みで、実力を隠して好機を待つこと、あるいは低い地位に甘んじることを指します。「雌」が「じ」と読まれがちですが、「し」が正しい読み方です。