Drug from foxgloves (9)
I believe the answer is:
digitalis
'drug from foxgloves' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for digitalis that I've seen before include "Drug derived from foxglove leaves" , "Heart drug prepared from foxglove leaves" , "Drug from foxgloves" , "plant making this drug?" , "Cardiac stimulant prepared from 11" .)