Female with pride in Sir Tristram’s birthplace, it’s said (7)
I believe the answer is:
lioness
'female with pride' is the definition.
(as in a pride of lions)
'sir tristram's birthplace it's said' is the wordplay.
'sir tristram's birthplace' becomes 'lyonnesse' (mythical country in Arthurian legend).
'it's said' shows a homophone (sound like).
'lyonnesse' sounds like 'LIONESS'.
'in' acts as a link.
(Other definitions for lioness that I've seen before include "Brave woman" , "Fierce female feline" , "Elsa, for one" , "Female pride member" , "Predator" .)