Graduate meets fool in plant (6)
I believe the answer is:
banana
'plant' is the definition.
(banana is a kind of plant)
'graduate meets fool' is the wordplay.
'graduate' becomes 'ba'.
'meets' means one lot of letters go next to another.
'fool' becomes 'nana' (I've seen this before).
'ba'+'nana'='BANANA'
'in' is the link.
(Other definitions for banana that I've seen before include "Fruit grown in hands" , "Yellow fruit with slippery skin" , "Tropical yellow fruit" , "Fruit with soft, sweet flesh" , "Elongated edible fruit" .)