Leguminous plant (5)
(Other definitions for lupin that I've seen before include "Flowering plant" , "bloomer" , "Garden plant with long, spiky flowers" , "Garden plant of the pea family" , "9 [BLOOM]" .)
'leguminous plant' is the definition.
(I know that vetch is a type of leguminous plant)
This is all the clue.
(Other definitions for vetch that I've seen before include "Climber" , "Wild climbing plant" , "Climbing plant of the pea family, cultivated as fodder" , "Weed" , "Wild plant with purple flowers" .)
'leguminous plant' is the definition.
(pea is a kind of leguminous plant)
This is the entire clue.
(Other definitions for pea that I've seen before include "Climbing plant; vegetable" , "Tiny stone" , "Ape this plant awkwardly" , "Common vegetable seed from pod" , "12 in a pod" .)