Masculine stratagem in rising river's working (8)
I believe the answer is:
employed
'working' is the definition.
('employed' can be similar in meaning to 'working')
'masculine stratagem in rising river's' is the wordplay.
'masculine' becomes 'm'.
'stratagem' becomes 'ploy' ('ploy' can be a synonym of 'stratagem'**).
'in' means one lot of letters goes inside another.
'rising' is a reversal indicator (going up in a down clue).
'river' becomes 'dee' (River Dee).
'dee' backwards is 'eed'.
'm'+'ploy'='mploy'
'mploy' put within 'eed' is 'EMPLOYED'.
(Other definitions for employed that I've seen before include "Working" , "in a job" , "Gave work to" , "Hired, made use of" , "Engaged in paid work" .)