- (chiefly Britain) An alumnus, especially of a public school.
- A former member of a group.
2011 September 24, Aled Williams, “Chelsea 4 - 1 Swansea”, in BBC Sport:
- Swansea named an unchanged side from their win over West Brom, and the visitors made an encouraging start, with Blues old boy Scott Sinclair prominent - Branislav Ivanovic had to make an important block to halt the winger's run.
- (Britain) An old man.
- I got talking to an old boy in the pub, and he told me what the village used to be like in the old days.
- (Britain) Affectionate term of address for a man of any age.
- Listen, old boy, I've got some news.
alumnus — see alumnus
an affectionate term of address for a man
- (alumnus) OB