You heard American soldier eating large fruit (4)
I believe the answer is:
ugli
'fruit' is the definition.
(I know that Ugli is a fruit)
'you heard american soldier eating large' is the wordplay.
'you heard' becomes 'U' (homophone of 'you').
'american soldier' becomes 'GI' (informal term for a US soldier).
'eating' is an insertion indicator.
'large' becomes 'L' (eg in clothes sizes).
'gi' placed around 'l' is 'gli'.
'u'+'gli'='UGLI'
(Other definitions for ugli that I've seen before include "Citrus fruit of the West Indies" , "Black/violet element" , "Hybrid of tangerine and grapefruit" , "Mottled tangelo hybrid" , "Plain-sounding fruit" .)