Leer (4)
I believe the answer is:
ogle
'leer' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ogle that I've seen before include "Look flirtatiously at" , "Cast flirtatious glance at" , "Cast lascivious glances" , "flirtatious look" , "Give the glad eye" .)