Times setter's seen cryptic crossword setter (7)
I believe the answer is:
ximenes
'crossword setter' is the definition.
(Ximenes was an early crossword setter)
'times setter's seen cryptic' is the wordplay.
'times' becomes 'x' (m times 4 is m x 4).
'setter's' becomes 'im' (I am - referring to the crossword setter).
'cryptic' indicates an anagram (a cryptic or obscure order of the letters).
'seen' is an anagram of 'enes'.
'x'+'im'+'enes'='XIMENES'
(Other definitions for ximenes that I've seen before include "Spanish inquisitor - pseudonym of famous crossword setter" , "fearful cardinal" , "Spanish grand inquisitor; see minx (anag.)" , "Grand Inquisitor and Archbishop of Toledo; see minx (anag.)" .)