Green’s Dictionary of Slang

cave n.1

1. (US Und.) a hiding place.

[US]C.G. Givens ‘Chatter of Guns’ in Sat. Eve. Post 13 Apr.; list extracted in AS VI:2 (1930) 132: cave, n. [...] a place of hiding.
[US]Monteleone Criminal Sl. (rev. edn).

2. (N.Z./US prison) a cell.

[US]C.G. Givens ‘Chatter of Guns’ in Sat. Eve. Post 13 Apr.; list extracted in AS VI:2 (1930) 132: cave, n. Cell.
[US]Goldin et al. DAUL 41/2: Cave. (Rare) A prison cell.
[NZ]D. Looser Boobslang [U. Canterbury D.Phil. thesis] 39/1: cave n. a cell.

3. (US black) one’s room, one’s home, one’s dwelling place.

[US] ‘Hotel Sl.’ in AS XIV:3 Oct. 239/2: cave Guest room.
[US] ‘Jiver’s Bible’ in D. Burley Orig. Hbk of Harlem Jive.
[US]Wentworth & Flexner DAS.

In compounds

cave cop (n.)

(US) a subway policeman.

[US]J. Maple Crime Fighter 13: Seven hours a day, I watched robbers and bag snatchers and pickpockets pass through the subway turnstiles on their way upstairs to where the money was [...] I was more than a cave cop.
cave dweller (n.)

1. (US) one who lives in the cellar of a slum tenement.

[US]J.A. Riis How the Other Half Lives 16: Not until five years after did the department succeed at last in ousting the ‘cave-dwellers’ and closing some five hundred and fifty cellars.

2. (US) a member of the old New York aristocracy [such aristocrats still lived in the dark, old mansions their families had built earlier in the century].

[US](con. 1890s) I.L. Allen City in Sl. (1995) 118: New York’s old aristocracy [...] mostly lived [...] in deep, dark, cool, cave-like mansions of grey stone and white marble. Wags, probably also by about 1890, were calling them cave dwellers, a term used for the older nobs down to the 1930s.

3. (N.Z. prison) one who spends nearly all his time in his cell.

[NZ]D. Looser Boobslang [U. Canterbury D.Phil. thesis] 39/1: cave-dweller n. = caveman [...] caveman (also captain caveman) n. an inmate who remains constantly in his cell.