Green’s Dictionary of Slang

(US) a bald-headed person, or one with a crewcut; such a haircut.

1949		Monteleone Criminal Sl. (rev. edn).
1955		W. White ‘Wayne University Sl.’ AS XXX:4 303: cue ball [...] A crew haircut.
1960, 1975		(ref. to 1943) Wentworth & Flexner DAS 133/2: ‘Cueballs [are] the barber’s clients.’ A. Ostrow.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 50/1: cue ball n. a skinhead.