Endless humiliation for phoney (4)
I believe the answer is:
sham
'phoney' is the definition.
(I've seen this before)
'endless humiliation' is the wordplay.
'endless' means to remove the last letter.
'humiliation' becomes 'shame' (I've seen this before).
'shame' with its final letter removed is 'SHAM'.
'for' is the link.
(Other definitions for sham that I've seen before include "'Fake, pseudo (4)'" , "False and phoney" , "Phoney kind of hams" , "Counterfeit, fake" , "Unreal" .)