オールドボーイ
Meanings
1
old boy; alumnus; former member
Refers to a male graduate or former member of a school, club, or organization. Often used in contexts like school alumni associations or sports team alumni. The term is a direct loan from English 'old boy' and carries a similar connotation of camaraderie and shared history.
See also: OB
He serves as a secretary for the university's old boys' association.
The old boys of that soccer team got together and played a friendly match.