Parting word from esteemed leader in heroic novel (7)
I believe the answer is:
cheerio
'parting word' is the definition.
(cheerio means goodbye)
'esteemed leader in heroic novel' is the wordplay.
'leader' suggests taking the first letters.
'in' means one lot of letters goes inside another.
'novel' indicates an anagram.
The first letter of 'esteemed' is 'e'.
'heroic' anagrammed gives 'cherio'.
'e' inserted inside 'cherio' is 'CHEERIO'.
'from' acts as a link.
(Other definitions for cheerio that I've seen before include "Bye-bye" , "Expression used when leaving" , "British romance imprint" , "A hearty farewell, begins with applause" , "Say this before drinking" .)