Lentil or peanut (6)
I believe the answer is:
legume
'lentil or peanut' is the definition.
(I know that Lens culinaris is a type of legume)
This is the entire clue.
(Other definitions for legume that I've seen before include "A fruit that bears its seed in pods" , "Eg, pea, bean plant" , "Bean or pea, for example" , "Pea-family crop plant" , "Veg as pea, bean" .)