It's real; i.e. one of the ancient people (9)
I believe the answer is:
israelite
'one of the ancient people' is the definition.
The definition suggests a singular noun which matches the answer.
'it's real i e' is the wordplay.
'it's real i e' anagrams to 'ISRAELITE'.
However, I am not sure how this is indicated.
Can you help me to learn more?
(Other definitions for israelite that I've seen before include "For example, Nathanael" , "Ancient Hebrew" , "Tribesman" , "one of the chosen?" , "Old Hebrew" .)