Examinations reveal further cut on underside of hand (6)
I believe the answer is:
finals
'examinations' is the definition.
(final is a kind of examination)
'further cut on underside of hand' is the wordplay.
'further' becomes 'also' (I've seen this before).
'cut' means to remove the last letter.
'on underside of' says to put letters next to each other (in a down clue, some letters go below others).
'hand' becomes 'fin' (fin can humorously mean a hand).
'also' with its final letter taken off is 'als'.
'als' after 'fin' is 'FINALS'.
'reveal' is the link.
(Other definitions for finals that I've seen before include "Moral principles" , "University exams" , "Last exam at university" , "University examinations" , "Qualifying exams" .)