Charm with fondness losing head (7)
I believe the answer is:
enchant
'charm' is the definition.
(enchanting is a kind of charming)
'fondness losing head' is the wordplay.
'fondness' becomes 'penchant' (I've seen this before).
'losing head' means to remove the first letter.
'penchant' with its initial letter removed is 'ENCHANT'.
'with' acts as a link.
(Other definitions for enchant that I've seen before include "Hypnotise" , "Appeal" , "Beguile" , "Bewitch, charm" , "Entrance" .)