Epitaphs composed for the most fortunate (8)
I believe the answer is:
happiest
'most fortunate' is the definition.
('happy' can be similar in meaning to 'fortunate')
'epitaphs composed' is the wordplay.
'composed' indicates an anagram.
'epitaphs' is an anagram of 'HAPPIEST'.
'for the' is the link.
(Other definitions for happiest that I've seen before include "Most content" , "Most gay" , "extremely contented" , "Gladdest" , "Most contented and satisfied" .)