Resembling fruit is wrong (4-6)
I believe the answer is:
pear-shaped
'resembling fruit is wrong' is the definition.
I can't judge whether this defines the answer.
'fruit is wrong' is the wordplay.
'fruit' becomes 'pear' (pear is a kind of fruit).
'is wrong' becomes 'shaped' (I am not sure about this - if you are sure you should believe this answer much more).
'pear'+'shaped'='PEAR-SHAPED'
Can you help me to learn more?
(Other definitions for pear-shaped that I've seen before include "Fat at one end and thin at the other - all wrong!" , "With hips very wide compared to the upper body" , "Bottom-heavy: (gone) wrong" , "(Go) horribly wrong; like three Satie pieces" .)