Fiery Fred, that faithful fellow (7)
I believe the answer is:
trueman
'fiery fred' is the definition.
The definition suggests a singular noun which matches the answer.
'faithful fellow' is the wordplay.
'faithful' becomes 'true' (associated in meaning).
'fellow' becomes 'man' (fellow can mean a man).
'true'+'man'='TRUEMAN'
'that' is the link.
Can you help me to learn more?
(Other definitions for trueman that I've seen before include "English bowler" , "Yorkshire cricket star" .)