Lively turn I have put on (6)
I believe the answer is:
active
'lively' is the definition.
('active' can be similar in meaning to 'lively')
'turn i have put on' is the wordplay.
'turn' becomes 'act' (theatre**).
'i have' becomes 'ive'.
'put on' is a charade indicator (letters next to each other).
'act'+'ive'='ACTIVE'
(Other definitions for active that I've seen before include "kind of voice" , "Keeping busy or operative" , "Not extinct (of volcano)" , "Working; moving" , "Industrious" .)