Whack

[davemarc]

Regarding "crack is whack," I remember hearing it in New York City during
the anti-crack campaign years of the mid-1980s. The speaker was a recent
college grad who had entered publishing.

And just this morning I overheard a Manhattan security guard offer another
usage of "whack" to refer to a white woman "who thinks she's black."

Here's a related online usage from 1999:
http://www.epinions.com/mvie-review-3B56-16E0D62B-384592A5-prod1

David