Come again? (8)

'come again?' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for reappear that I've seen before include "make a comeback" , "Show over" , "return" , "Come into view again" , "Turn up again" .)
'come again?' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for recur that I've seen before include "Come round again" , "expected to return" , "come back to one's mind" , "Return to mind" , "Perseverate" .)
(Other definitions for sorry that I've seen before include "I beg your pardon" , "Contrite" , "Feeling penitent" , "Feeling regret" , "I didn't quite catch that?" .)
'come again?' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for what that I've seen before include "I didn't hear" , "Eh?" , "That which - come again!" , "Which thing?" , "Interrogatory word" .)