United StatesUnited KingdomAustraliaCanadainformalderogatoryslang
A pejorative term for a person whose head is perceived as unusually large, round, or melon‑shaped; used to mock physical appearance.
2.
United StatesUnited KingdomAustraliaCanadainformalderogatory
A disparaging reference to a person's mind or intellect, implying foolishness, stupidity, or thoughtlessness (as in references to 'what's in that melon head of yours').