Green’s Dictionary of Slang

(US black) the buttocks, the posterior.

1929		(con. WWI) J.B. Wharton Squad 218: You guys c’n go back an’ take a good, long rest—in a pig’s pink hind-end.
1943		W. Guthrie Bound for Glory (1969) 207: You ought to have your little hind end blistered!
1967–70		in DARE.
1986		L. Pederson LAGS Concordance [DARE].