Akademik

на холостяцкую ногу
НА ХОЛОСТЯЦКУЮ (ХОЛОСТУЮ) НОГУ жить coll
[PrepP; these forms only; adv; fixed WO]
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(of a man) (to live) without the comforts characteristic of family life:
- (live) like a (true <typical>) bachelor;
- (lead <live>) the bachelor life (the life of a bachelor).

Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. . 2004.