He'd read about a girl with Titian hair (7)
I believe the answer is:
redhead
'he'd read about a girl with titian hair' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'he'd read about' is the wordplay.
'about' indicates an anagram.
'hed'+'read'='hedread'
'hedread' anagrammed gives 'REDHEAD'.
Can you help me to learn more?
(Other definitions for redhead that I've seen before include "One with distinctive hair" , "Blue Australian" , "One with rufous hair" , "Bluey" , "Ginger-haired person" .)