Keen listener gathers tips on grapevine (5)
I believe the answer is:
eager
'keen' is the definition.
(I've seen this before)
'listener gathers tips on grapevine' is the wordplay.
'listener' becomes 'ear' (body part which hears or listens).
'gathers' means one lot of letters goes inside another.
'tips on grapevine' becomes 'ge' (I can't explain this - if you can you should give a lot more credence to this answer).
'ear' going around 'ge' is 'EAGER'.
Can you help me to learn more?
(Other definitions for eager that I've seen before include "Keen, avid" , "Anxious" , "hungry" , "Showing keen interest" , "Longing to see" .)