Active; forceful (7)
I believe the answer is:
dynamic
This clue is a double definition.
'active' is the first definition.
(I know that active can be written as dynamic)
'forceful' is the second definition.
(similar in meaning)
(Other definitions for dynamic that I've seen before include "Forceful" , "I'm Candy (anag) - full of beans" , "Having power" , "Vigorous and effective" , "Powerful and vigorous" .)