Brown river sweeping away hotel (5)
I believe the answer is:
umber
'brown' is the definition.
(I know that umber is a type of brown)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for umber that I've seen before include "Yellow-brown pigment" , "Yellowish-brown pigment" , "Brown earthy mineral" , "Brownish pigment" , "Natural colouring matter, dark brown" .)