Strong-scented herb (5)
I believe the answer is:
tansy
'strong-scented herb' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tansy that I've seen before include "plant for medicinal use" , "Plant with yellow flowers" , "Flowering plant" , "Herb used as seasoning" , "Aromatic wild plant" .)