He was fabulously touchy about gold (5)
I believe the answer is:
midas
'he was fabulously touchy' is the definition.
The definition suggests a singular noun which matches the answer.
'about gold' is the wordplay.
I cannot quite understand how this works, but
'about' could be 'a' (abbreviation in Chambers) and 'a' is located in the answer.
The remaining letters 'mids' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for midas that I've seen before include "Mythical king with golden touch" , "Legendary king who could turn everything to gold" , "Legendary king whose touch turned anything to gold" , "His touch made gold" , "King of Phrygia who had a golden touch" .)