Energetic performing group I have shortly indicated (6)
I believe the answer is:
active
'energetic' is the definition.
(similar in meaning)
'performing group i have shortly indicated' is the wordplay.
'performing group' becomes 'act' (I've seen this before).
'i have' becomes 'I've' (contraction of 'I have').
'shortly' means to remove the last letter.
'indicated' becomes 'e' (I am not sure about this - if you are sure you should believe this answer much more).
'ive' with its final letter taken off is 'iv'.
'act'+'iv'+'e'='ACTIVE'
Can you help me to learn more?
(Other definitions for active that I've seen before include "On the go" , "Keeping busy, not lazy" , "Energetic, moving" , "Vigorously moving" , "Busy, energetic" .)