Pure breed regularly okay with daughter (7)
I believe the answer is:
refined
'pure' is the definition.
(similar in meaning)
'breed regularly okay with daughter' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'okay' becomes 'fine' (both are ways of saying 'yes').
'with' means one lot of letters go next to another.
'daughter' becomes 'd' (genealogical abbreviation).
The alternating letters of 'breed' are 're'.
're'+'fine'+'d'='REFINED'
(Other definitions for refined that I've seen before include "Freed from impurities by processing" , "Just like the cultured" , "With impurities removed" , "Tasteful; genteel" , "Discerning" .)