He's included in the nobility (3)
I believe the answer is:
nob
'he's included in the nobility' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
This is all the clue.
Can you help me to learn more?
(Other definitions for nob that I've seen before include "A slang toff - c'est bon" , "Jack" , "A slangy head" , "A slangy person of high rank - c'est bon" , "A posh gent - c'est bon" .)