Green’s Dictionary of Slang

1. (US campus) a socially unacceptable person.

[1943		(con. 1861-5) B.I. Wiley Life of Johnny Reb 268: The Confederate surgical corps was made up wholly of ‘culls’ novices and quacks].
1975		G. Underwood ‘Razorback Sl.’ in AS L:1/2 57: cull n 1: Person considered socially unacceptable.

2. (US prison) a physically weak convict.

1971–2

C. Shafer ‘Catheads [...] and Cho-Cho Sticks’ in Abernethy Bounty of Texas (1990) 202: cull, n. – a convict given a soft job because he could not handle a hard job to which he was previously assigned.

3. (US campus, spec. fraternity) anyone rejected for membership in a fraternity or sorority.

1975

G. Underwood ‘Razorback Sl.’ in AS L:1/2 57: cull n [...] 2: Rushee rejected for membership by a fraternity or sorority.

4. (US) a girl or woman categorised as unattractive.

1977

R. Dennis Hump’s First Case 1280: [A] young black girl. Not prime, Hump thought, but not a cull either.