A look of amiable eroticism (4)
I believe the answer is:
leer
'a look' is the definition.
(I know that leer is a more specific form of the action look)
'of amiable eroticism' is the wordplay.
'of' indicates a hidden word.
'LEER' is hidden in the letters of 'amiable eroticism'.
(Other definitions for leer that I've seen before include "Look lasciviously at" , "Lascivious gaze" , "Ogle, smirk" , "Give sly look" , "Gaze lasciviously at" .)