Some retired villagers showing bitterness (4)
I believe the answer is:
gall
'bitterness' is the definition.
('gall' can be a synonym of 'bitterness')
'some retired villagers' is the wordplay.
'retired' is a reversal indicator.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'llag' is hidden within 'villagers'.
'llag' backwards is 'GALL'.
'showing' is the link.
(Other definitions for gall that I've seen before include "Impertinence" , "Audacity" , "Impudence; bitterness" , "Bitterness of feeling or bodily bladder" , "Bold impudent behaviour; abnormal growth on tree" .)