old boy

noun old boys · OB

1. UK An alumnus, especially of a public school.
2. A former member of a group. 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.
3. A man with an established network of friends who assist one another in social and business situations; a good old boy. The fact that they have waited to leave messages and have left hand-written evidence indicates to me that they don't believe they are going to be apprehended, that they have friends in 'higher places.' This is a small town. Everybody knows everybody. That 'ol boy' chuminess ^([sic]).
4. UK, informal An elderly 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.
5. UK, dated A familiar term of address for a man of any age. Listen, old boy, I've got some news.