Long tale about Melibee, ultimately (5)
I believe the answer is:
yearn
'long' is the definition.
('yearn' can be a synonym of 'long')
'tale about melibee ultimately' is the wordplay.
'tale' becomes 'yarn' ('yarn' can be a synonym of 'tale').
'about' indicates putting letters inside.
'ultimately' says to take the final letters.
The final letter of 'melibee' is 'e'.
'yarn' placed around 'e' is 'YEARN'.
(Other definitions for yearn that I've seen before include "Desire strongly" , "Long - pine" , "Pant - pine" , "Ache, crave" , "Have strong desire" .)