Lecherous look making us stagger backwards (4)
I believe the answer is:
leer
'lecherous look' is the definition.
(I've seen this before)
'stagger backwards' is the wordplay.
'stagger' becomes 'reel' (both can mean to move around without balance).
'backwards' is a reversal indicator.
'reel' written backwards gives 'LEER'.
'making us' is the link.
(Other definitions for leer that I've seen before include "Ogle, smirk" , "Stare suggestively" , "Lewd look" , "Suggestive or sneering look" , "unpleasant look" .)