Perhaps Odysseus conceals this ecstatic expression of feeling (8)
I believe the answer is:
rhapsody
'this ecstatic expression of feeling' is the definition.
(I've seen this before)
'perhaps odysseus conceals' is the wordplay.
'conceals' indicates the answer is hidden within the clue.
'RHAPSODY' is hidden in the letters of 'perhaps odysseus'.
(Other definitions for rhapsody that I've seen before include "Ecstatic written or romantic musical composition" , "Moving piece of music" , "Emotional musical piece - epic poem" , "Ecstatic utterance" , "Expression of ecstatic enthusiasm" .)