Stick flap back on (5)
I believe the answer is:
baton
'stick' is the definition.
(thesaurus)
'flap back on' is the wordplay.
'flap' becomes 'tab' (I've seen this before).
'back' shows that the letters should be reversed in order.
'tab' backwards is 'bat'.
'bat'+'on'='BATON'
(Other definitions for baton that I've seen before include "Relay race stick" , "Conductor's wand" , "It's passed in a relay race" , "Club, stick" , "Short stick" .)