River current provides inclination (4)
I believe the answer is:
ramp
'inclination' is the definition.
(an inclined surface)
'river current' is the wordplay.
'river' becomes 'r' (abbreviation for river).
'current' becomes 'amp' (electricity).
'r'+'amp'='RAMP'
'provides' acts as a link.
(Other definitions for ramp that I've seen before include "Slope - racket" , "Inclination - swindle" , "fleece?" , "Sloping platform" , "An elevation for pram" .)