Steady revenue is somewhat reduced (4)
I believe the answer is:
even
'steady' is the definition.
(associated in meaning)
'revenue is somewhat reduced' is the wordplay.
'is somewhat reduced' indicates a hidden word.
'EVEN' is hidden in the letters of 'revenue'.
(Other definitions for even that I've seen before include "Regular - smooth" , "happening to take time off?" , "Deep crisp snow seen on Boxing Day also this" , "on level terms" , "Peaceful" .)