Noun old boy has 3 senses
- old boy, old man - a familiar term of address for a man
--1 is a kind of man, adult male
- old boy - a vivacious elderly man
--2 is a kind of oldster, old person, senior citizen, golden ager
- old boy - a male ex-pupil of a school
--3 is a kind of alumnus, alumna, alum, graduate, grad
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