- [sometimesO- B-]Chiefly Brit., Informal an alumnus, esp. of a boys' preparatory school
- a man belonging to a social, professional, etc. group regarded as prestigious or influential, whose members provide one another with assistance or preferential treatment
old boyold boy
- Chiefly British A graduate of a public school for boys.
- A man who is a member of an old-boy network.
(plural old boys)
- (chiefly UK) An alumnus, especially of a public school.
- (UK) Affectionate term of address for a man.
- Listen, old boy, I've got some news.
- A former member of a group