Repeatedly (5,3,5)
I think it could be either:
again and again
'repeatedly' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for again and again that I've seen before include "Repeatedly" , "Many times" , "Continually" , "repetition" .)
'repeatedly' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for time after time that I've seen before include "When illegal drinkers used to enjoy themselves" , "Repeatedly" .)