Green’s Dictionary of Slang

1. a school child who has been rejected by their fellows.

1986		H.B. Gilmour Pretty in Pink 10: There were the richies, and then there were the zoids: the freaks, the outsiders, the zombies. And the girl he was looking at now was definitely a zoid.
1987		G.A. Fine With the Boys 175: Zoid was defined by its originator as referring to a boy who is a ‘loser’ [...] and is not a member of any group (as in the sarcastic put-down: ‘You’re a zoid; ya know it?’).

2. (US campus) a fan of punk rock and its attendant styles.

1984		Eble Campus Sl. Sept.
1996		Eble Sl. and Sociability 36: Slang words formed by clipping sounds from the beginning of the word are [...] zoid ‘fan of punk rock music and styles’, from freakazoid.