Hazel, be it nuts or a girl’s name (9)
I believe the answer is:
elizabeth
'a girl's name' is the definition.
(I've seen this before)
'hazel be it nuts' is the wordplay.
'nuts' indicates anagramming the letters (nuts can mean crazy).
'hazel'+'be'+'it'='hazelbeit'
'hazelbeit' with letters rearranged gives 'ELIZABETH'.
'or' acts as a link.
(Other definitions for elizabeth that I've seen before include "The Virgin Queen" , "- Barrett Browning, English poet" , "Fry" , "-- Taylor, film actress" , "woman revealed" .)