Come again about unfinished remedy (5)
I believe the answer is:
recur
'come again' is the definition.
(I've seen this before)
'about unfinished remedy' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'unfinished' means to remove the last letter.
'remedy' becomes 'cure' (synonyms).
'cure' with its last letter taken off is 'cur'.
're'+'cur'='RECUR'
(Other definitions for recur that I've seen before include "Repeat" , "Happen again or repetitively" , "Come round again" , "Be repeated" , "expected to return" .)