Heard couple have fruit (4)
I believe the answer is:
pear
'fruit' is the definition.
(I know that pear is a type of fruit)
'heard couple' is the wordplay.
'heard' indicates a 'sounds like' (homophone) clue.
'couple' becomes 'pair' (synonyms).
'pair' sounds like 'PEAR'.
'have' is the link.
(Other definitions for pear that I've seen before include "Variety of pome" , "Fruit; sounds like duo" , "Alternative to apple" , "Tapering fleshy fruit - reap it" , "Avocado" .)