Definition from Wiktionary, the free dictionary
- Used other than as an idiom: see only, son.
- He was the only son to go to college.
- A sole male child among multiple siblings.
1991 November 18, Alessandra Stanley, “The Symbols Spawned by a Killing”, in New York Times:
- Mr. Doyle, an only son, grew up with the undivided attention of affectionate parents and two doting sisters.
sole male child