Nonsense exclusively seen in Times (7)
I believe the answer is:
baloney
'nonsense' is the definition.
(baloney is a kind of nonsense)
'exclusively seen in times' is the wordplay.
'exclusively' becomes 'alone' (synonyms).
'seen in' means one lot of letters goes inside another.
'times' becomes 'by' (both can mean 'multiplied by').
'alone' inserted inside 'by' is 'BALONEY'.
(Other definitions for baloney that I've seen before include "Tosh" , "Tripe < , smoked sausage" , "Nonsense; lean yob (anag)" , "Cobblers" , "foolish talk!" .)