Practise – tries in cut grass (8)
I believe the answer is:
rehearse
'practise' is the definition.
(I know that practise can be written as rehearse)
'tries in cut grass' is the wordplay.
'tries' becomes 'hears' (as in trying or hearing in a trial).
'in' is an insertion indicator.
'cut grass' becomes 'ree' (I can't explain this - if you can you should give a lot more credence to this answer).
'hears' placed inside 'ree' is 'REHEARSE'.
Can you help me to learn more?
(Other definitions for rehearse that I've seen before include "Prepare for a stage production" , "Practice for the performance" , "Recite - try out" , "Train" , "Practise before performing in public" .)