Tries again with a learner in practice session (9)
I believe the answer is:
rehearsal
'practice session' is the definition.
(rehearsal is a kind of practice session)
'tries again with a learner' is the wordplay.
'tries again' becomes 'rehears' ('hears' can be a synonym for 'tries' so perhaps 'rehears' is OK for 'tries again').
'with' is a charade indicator (letters next to each other).
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'rehears'+'a'+'l'='REHEARSAL'
'in' is the link.
(Other definitions for rehearsal that I've seen before include "Preparation for a show" , "Practice - run-through" , "preparation in house?" , "Practice session in preparation for public performance" , "Drill" .)