Dreamy sailor roused to ecstasy (6)
I believe the answer is:
absent
'dreamy' is the definition.
(thesaurus)
'sailor roused to ecstasy' is the wordplay.
I cannot really see how this works, but
'sailor' could be 'ab' (abbreviation for able seaman) and 'ab' is found within the answer.
'ecstasy' could be 'e' (informal term for the drug) and 'e' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for absent that I've seen before include "Forgetful, with mind on other things" , "Away" , "Not present - vacuous" , "Not at a specified place" , "nowhere to be seen" .)