Though humble, he has a fortune (5)
I believe the answer is:
helot
'though humble he has a fortune' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'he has a fortune' is the wordplay.
'has' means one lot of letters go next to another.
'a fortune' becomes 'lot' (as in a person's lot in life).
'he'+'lot'='HELOT'
Can you help me to learn more?
(Other definitions for helot that I've seen before include "downtrodden?" , "Spartan slave" , "Hotel (anag) - serf" , "Serf of ancient Sparta" , "Spartan serf" .)