Sensual dipper's bottom visible in waterway (6)
I believe the answer is:
carnal
'sensual' is the definition.
('carnal' can be a synonym of 'sensual')
'dipper's bottom visible in waterway' is the wordplay.
'bottom' suggests the final letters.
'visible in' indicates putting letters inside.
'waterway' becomes 'canal' (I've seen this before).
The last letter of 'dipper' is 'r'.
'r' going within 'canal' is 'CARNAL'.
(Other definitions for carnal that I've seen before include "Animal" , "Sexual" , "Earthly" , "Of the flesh, not spiritual" , "Relating to physical needs" .)