Angry gesture when pals break up (4)
I believe the answer is:
slap
'angry gesture' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'pals break up' is the wordplay.
'break up' indicates anagramming the letters.
'pals' is an anagram of 'SLAP'.
'when' is the link.
Can you help me to learn more?
(Other definitions for slap that I've seen before include "Make-up (slang)" , "Strike with the palm" , "Cuff" , "Blow (in face, on back, wrist)" , "Right" .)