The least bit; an iota: doesn't give a whit what was said; not a whit afraid. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "whit" in a sentence
"The mourning warbler's song, as I heard it, was like this: _Whit whit whit_, _wit wit_."
"This is his song, or what answers to a song, but I have seen him when he would do nothing but repeat incessantly a quick trisyllabic call, _whit, whit, whit_; corresponding, I suppose, to the well-known _whit_ with which the phoebe sometimes busies himself in a similar manner."
"John Cusack, equipped with his typical black suit and precision-guided whit, is the assassin, Brand Hauser, who has been hired to take out a high-profile target, Omar Sharif (not the real one)."