Green’s Dictionary of Slang

1. (US) derog. term for a black person; also attrib.

1972		B. Rodgers Queens’ Vernacular 168: raisin-hunting looking for a black partner in the black sections of town. [...] raisin queen white who turns to black lovers.
1983		I.L. Allen Lang. of Ethnic Conflict 46: Color Allusions, Other than ‘Black’ and ‘Negro’: [...] raisin [perhaps from the play and 1961 movie Raisin in the Sun].

2. (N.Z.) an old person.

1991		D. Jenkins You Gotta Play Hurt 126: ‘If the old raisin doesn’t die soon, my rich little clit won’t have too many good years left’.
2003		McGill Reed Dict. of N.Z. Sl.

3. (US) in pl., the testicles.

2017

S.M. Jones August Snow [ebook] ‘I can do anything I want in my house, pork chop [...] Including clipping your fucking raisins’.