Abandon fool perhaps, losing heart (6)
I believe the answer is:
desert
'abandon' is the definition.
('desert' can be a synonym of 'abandon')
'fool perhaps losing heart' is the wordplay.
'fool perhaps' becomes 'dessert' (fool is a type of dessert).
'losing heart' means to remove the middle letters.
'dessert' with its centre removed is 'DESERT'.
(Other definitions for desert that I've seen before include "Kalahari, e.g." , "Abandon; barren waste" , "Leave; arid area" , "Abandon in barren terrain" , "Run away; desolate area" .)