Pure red tea stirred by a French man or woman (13)
I believe the answer is:
unadulterated
'pure' is the definition.
(similar in meaning)
'red tea stirred by a french man or woman' is the wordplay.
'stirred' indicates an anagram.
'by' is a charade indicator (letters next to each other).
'a french' becomes 'un' ('a' in French).
'man or woman' becomes 'adult' (an adult person).
'red'+'tea'='redtea'
'redtea' anagrammed gives 'erated'.
'un'+'adult'='unadult'
'erated' after 'unadult' is 'UNADULTERATED'.
(Other definitions for unadulterated that I've seen before include "Total" , "Simple" , "not cut" , "Pure" .)