Diverted in midstream, use discretion (6)
I believe the answer is:
amused
'diverted' is the definition.
('amuse' can be a synonym of 'divert')
'in midstream use discretion' is the wordplay.
'in' indicates a hidden word.
'AMUSED' can be found hidden inside 'midstream use discretion'.
(Other definitions for amused that I've seen before include "Tickled pink" , "Medusa (anag)" , "Mildly diverted or entertained" , "Victoria reputedly wasn't" , "Made (someone) laugh" .)