old boy

noun5

1. •
   (UK) An alumnus, especially of a public school.
2. •
   A former member of a group.
3. •
   (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.
4. •
   (UK, old-fashioned) A familiar term of address for a man of any age.

   • Listen, old boy, I've got some news.
5. •
   A man with an established network of friends who assist one another in social and business situations; a good old boy.