Last bit of puzzle you had looked at (4)
I believe the answer is:
eyed
'looked at' is the definition.
(I've seen this before)
'last bit of puzzle you had' is the wordplay.
'last bit of' says to take the final letters.
'you' becomes 'ye'.
'had' becomes 'd' (I've seen this in other clues).
The last letter of 'puzzle' is 'e'.
'e'+'ye'+'d'='EYED'
(Other definitions for eyed that I've seen before include "Ogled" , "Looked at closely" , "examined" , "Stared at" , "Watched with interest" .)