Epic poem of perhaps 'Odyssey' (8)
I believe the answer is:
rhapsody
'epic poem' is the definition.
(rhapsody is a kind of epic poem)
'of perhaps odyssey' is the wordplay.
'of' indicates a hidden word.
'RHAPSODY' can be found hidden inside 'perhaps odyssey'.
(Other definitions for rhapsody that I've seen before include "Gershwin wrote of one in blue" , "Irregular and emotional musical composition" , "Moving piece of music" , "Ecstatic expression of feeling" , "Heroic poem or piece of music" .)