On the shelf, pawn love token (6)
I believe the answer is:
pledge
'love token' is the definition.
(pledge can mean something given as a token)
'on the shelf pawn' is the wordplay.
'on' means one lot of letters go next to another.
'the shelf' becomes 'ledge' ('ledge' can be a synonym of 'shelf').
'pawn' becomes 'p'.
'ledge' after 'p' is 'PLEDGE'.
(Other definitions for pledge that I've seen before include "Promise (to abstain?)" , "Plight" , "Bond" , "make toast" , "Vow; security" .)