Encore from Gaga incredible (5)
I believe the answer is:
again
'encore' is the definition.
(I've seen this before)
'from gaga incredible' is the wordplay.
'from' says the answer is hidden in the clue.
'AGAIN' can be found hidden inside 'gaga incredible'.
(Other definitions for again that I've seen before include "Repeatedly" , "10 10 [AGAIN" , "On the other hand" , "Ocne more" , "second term" .)