Old Native American, key one of five inspiring long novel (9)
I believe the answer is:
algonquin
'old native american' is the definition.
'Algonquin' can be an answer for 'american' (Algonquin is an example). I am unsure of the 'old native' bit.
'key one of five inspiring long novel' is the wordplay.
'key' becomes 'A' (musical key).
'one of five' becomes 'quin' (short for quintuplet, one of five children).
'inspiring' means one lot of letters goes inside another.
'novel' is an anagram indicator (letters in a new or novel order).
'a'+'quin'='aquin'
'long' anagrammed gives 'lgon'.
'aquin' going around 'lgon' is 'ALGONQUIN'.
Can you help me to learn more?
(Other definitions for algonquin that I've seen before include "Indian language" , "native language" .)