Eager to listen (3,4)
I believe the answer is:
all ears
'eager to listen' is the definition.
(if someone is 'all ears' they're paying attention)
This is the entire clue.
(Other definitions for all ears that I've seen before include "Being very attentive" , "Listening attentively" , "description of cornfield?" , "Prepared to listen" , "Very alert" .)