Club with advantage (5)
I believe the answer is:
wedge
'club' is the definition.
(type of golf club)
'with advantage' is the wordplay.
'with' becomes 'w' (abbreviation).
'advantage' becomes 'edge' (having the edge is having an advantage).
'w'+'edge'='WEDGE'
(Other definitions for wedge that I've seen before include "Tapering object pushed into a gap - golf club" , "Tapering piece" , "Piece of wood thick at one end, thin at other" , "Tapering block" , "Slice" .)