Growing anger? (6)
I believe the answer is:
nettle
I believe this is a double definition.
'growing' is the first definition.
(I've seen this before)
'anger?' is the second definition.
(I've seen this before)
(Other definitions for nettle that I've seen before include "Stinging plant; annoy" , "Annoy; common weed" , "Irritate, annoy" , "urticaceous plant" , "Plant to irritate" .)