Label club the wrong way (3)
I believe the answer is:
tab
'label' is the definition.
(thesaurus)
'club the wrong way' is the wordplay.
'club' becomes 'bat' (bat is a kind of club).
'the wrong way' shows that the letters should be reversed in order.
'bat' written backwards gives 'TAB'.
(Other definitions for tab that I've seen before include "Text indent key" , "Small flap - bill" , "Flap; meal bill" , "Marker" , "Kind of label for bat" .)