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' (an abbreviation for learner driver written twice).
'absorbed by' is an insertion indicator.
'ecstasy' becomes 'joy' (I've seen this in another clue).
'll' going into '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" .)