One of seven letters from country admitting old novelist and, separately, me (5,7)
I believe the answer is:
roman numeral
'one of seven letters' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'from country admitting old novelist and separately me' is the wordplay.
I cannot quite see how this works, but
'from' could be 'o' (I've seen this in other clues) and 'o' is found in the answer.
'novelist' could be 'mann' (I have seen 'German novelist ' mean 'mann' so perhaps 'novelist' could also mean 'mann') and 'mann' is found in the answer.
'me' is found in the answer.
'country' could be 'rural' (similar in meaning) and 'rural' is located in the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for roman numeral that I've seen before include "I for one!" , "Such as V, X or L" , "I say" , "Eg, X or V or M" , "I, perhaps" .)