A step up in enterprise, really (5)
I believe the answer is:
riser
'a step up' is the definition.
(I've seen this before)
'in enterprise really' is the wordplay.
'in' indicates a hidden word.
'RISER' is hidden in the letters of 'enterprise really'.
(Other definitions for riser that I've seen before include "A bit of a flight" , "one of a number in flight" , "found on the staircase" , "Vertical piece between stair steps" , "Front of a staircase step" .)