Sailor losing heart, away getting fish (5)
I believe the answer is:
trout
'fish' is the definition.
(trout is a kind of fish)
'sailor losing heart away getting' is the wordplay.
'sailor' becomes 'tar' (tar is a kind of sailor).
'losing heart' means to remove the middle letters.
'away' becomes 'out' ('out' can be a synonym of 'away').
'getting' says to put letters next to each other.
'tar' with its middle taken out is 'tr'.
'tr'+'out'='TROUT'
(Other definitions for trout that I've seen before include "old bag" , "one may be hooked" , "Freshwater game fish" , "Fish (associated with Schubert?)" , "Commonly caught fish" .)