Look like Groucho
I believe the answer is:
leer
'look like groucho' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for leer that I've seen before include "Stare suggestively" , "Suggestive or sneering look" , "Suggestive or sneering grin" , "Ogle, smirk" , "Look lasciviously at" .)