Students absorbed by ecstasy trip (5)
I believe the answer is:
jolly
'trip' is the definition.
(I've seen this before)
'students absorbed by ecstasy' is the wordplay.
'students' becomes 'LL' (two abbreviations for learner).
'absorbed by' is an insertion indicator.
'ecstasy' becomes 'joy' (I've seen this in another clue).
'll' inserted inside 'joy' is 'JOLLY'.
(Other definitions for jolly that I've seen before include "' - - boating weather' (song)" , "Very pleasurable" , "all-expenses-paid trip" , "Good-humoured, cheerful" , "Expression denoting hearty, sporting type of girl" .)