Stalk learner seen among Vegas rollers after training (7)
I believe the answer is:
pedicle
'stalk' is the definition.
(stalk-like part of an organ)
'learner seen among vegas rollers after training' is the wordplay.
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'seen among' is an insertion indicator.
'vegas rollers' becomes 'dice' (I've seen this in another clue).
'after' means one lot of letters go next to another.
'training' becomes 'PE' (Physical Education).
'l' put inside 'dice' is 'dicle'.
'dicle' after 'pe' is 'PEDICLE'.
(Another definition for pedicle that I've seen is " Stalk-like connecting structure".)