"That'll teach ya!" (3)
I believe the answer is:
hah
(Another definition for hah that I've seen is " Expression of surprise (one letter short of a laugh)".)
I've seen this clue in the Universal.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free.
Check out my app
or
learn more
about the Crossword Genius project.