Lewd look (4)
I believe the answer is:
leer
'lewd look' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for leer that I've seen before include "Give sly look" , "Lewd look" , "Look lecherously" , "Suggestive or sneering look" , "Gaze lasciviously at" .)