rude slang To have nothing or only the slightest amount (of something) at all. Often used in negative constructions to emphasize a complete and utter lack of something. I spent a whole day in the library doing research, but I don't have jack-shit to use for my thesis. The cops have been investigating the crime for years, but they still have jack-shit in terms of hard evidence.
See also: have
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.