Say again, repeat (7)
I believe the answer is:
iterate
This clue is a double definition.
'say again' is the first definition.
(to iterate is say something again)
'repeat' is the second definition.
(I know that iterate is a more specific form of repeat)
(Other definitions for iterate that I've seen before include "State repeatedly, say again" , "Recapitulate" , "Say again, repeat" , "Utter or perform repeatedly" , "Repeat, state again" .)