Keen listener gathering tips on grapevine (5)
I believe the answer is:
eager
'keen' is the definition.
(I've seen this in another clue)
'listener gathering tips on grapevine' is the wordplay.
'listener' becomes 'ear' (body part which hears or listens).
'gathering' means one lot of letters goes inside another (gather can mean to acquire or bring in).
'tips on' means to remove the middle letters (only the tips of the word).
'grapevine' with its middle removed is 'ge'.
'ear' going around 'ge' is 'EAGER'.
(Other definitions for eager that I've seen before include "passionate" , "Keenly interested" , "willing" , "Anxious" , "Desperate" .)