Brown points a river out (5)
I believe the answer is:
tawny
'brown' is the definition.
(thesaurus)
'points a river out' is the wordplay.
'points' becomes 'wn' (**).
'a river' becomes 'tay' (Scottish river).
'out' means one lot of letters goes inside another.
'wn' inserted into 'tay' is 'TAWNY'.
(Other definitions for tawny that I've seen before include "Orange-brown in colour" , "Yellowish-brown - kind of owl" , "Brownish-yellow" , "Golden brown" , "port" .)