Feel bitter about pressure to avoid attending (6)
I believe the answer is:
resent
'feel bitter' is the definition.
(I've seen this before)
'about pressure to avoid attending' is the wordplay.
I cannot really understand how this works, but
'about' could be 're' (regarding) and 're' is found in the answer.
The remaining letters 'sent' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for resent that I've seen before include "Feel aggrieved at" , "Hold bitter memory, begrudge" , "Dislike" , "Feel bitter or envious" , "Feel or show annoyance" .)