Tackle good listener (4)
I believe the answer is:
gear
'tackle' is the definition.
(I've seen this before)
'good listener' is the wordplay.
'good' becomes 'g' (abbreviation).
'listener' becomes 'ear' (body part which hears or listens).
'g'+'ear'='GEAR'
(Other definitions for gear that I've seen before include "Unusually good" , "Set of wheels working by engaging cogs" , "Toothed wheel used when changing speed" , "Trendy clothes - changed in car?" , "often changed when driving" .)