Fesses up to (6)
I believe the answer is:
admits
'fesses up to' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for admits that I've seen before include "Confesses or allows to enter" , "Allows in or accepts guilt" , "Takes in" , "Owns up or lets in" , "Does not deny" .)