Be deceived by (4,3)
I believe the answer is:
fall for
'be deceived by' is the definition.
(synonyms)
This is all the clue.
(Other definitions for fall for that I've seen before include "Succumb to charm or love" , "Take romantic liking to- steady on!" , "Have romantic feelings for - or be taken in by?" , "Be taken in by - romantically?" , "Be deceived" .)