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 see how this works, but
'about' could be 're' ('re' means regarding or about) and 're' is located in the answer.
The remaining letters 'sent' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
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" .)