He has no fancy ideas about a catalogue (7)
I believe the answer is:
realist
'he has no fancy ideas' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'about a catalogue' is the wordplay.
'about' becomes 'rea' (I've seen this in other clues).
'a catalogue' becomes 'list' (I've seen this in another clue).
'rea'+'list'='REALIST'
Can you help me to learn more?
(Other definitions for realist that I've seen before include "Practical type" , "One who sees things in a practical way" , "Writer like Balzac" , "Pragmatist" , "Practical sort" .)