Plant I’d return to students (4)
I believe the answer is:
dill
'plant' is the definition.
(dill is a kind of plant)
'i'd return to students' is the wordplay.
'return' is a reversal indicator.
'to students' becomes 'll' (**).
'id' backwards is 'di'.
'di'+'ll'='DILL'
(Other definitions for dill that I've seen before include "Herb with feathery leaves and spicy seeds" , "Herb with thread-like foliage used as seasoning" , "Herb used in cooking" , "Plant of the celery family; leaf is a herb, seeds a spice" , "Herb used in pickles" .)