A couple object to such a fruit (10)
I believe the answer is:
gooseberry
'a couple' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'object to such a fruit' is the wordplay.
'object' becomes 'goose' (goose is a kind of object).
'to such a fruit' becomes 'berry' (berry is a kind of fruit).
'goose'+'berry'='GOOSEBERRY'
Can you help me to learn more?
(Other definitions for gooseberry that I've seen before include "it bears fruit" , "Fruit - unwanted third person" , "One unwelcome near passion" , "Third-party" , "Some intruders play it" .)