crackerbox, n. — Green’s Dictionary of Slang

crackerbox n.

[crackers adj. + SE box; pun on SE]

(US)

1. an eccentric, a madman.

1983

A-Team [TV script] I’ll find out who those crackerboxes are.

2. a psychiatric institution.

1989

R. Atkinson Long Gray Line (1990) 327: Funny farm, loony bin, cuckoo’s nest, booby hatch, nut house, cracker box, psycho ward.

3. see under cracker n.³

4. see under cracker n.⁴