Warrior woman in river (6)
I believe the answer is:
amazon
I believe this clue is a triple definition!
'warrior' is the first definition.
(I've seen this before)
'woman' is the second definition.
(amazon is a kind of woman)
'in' acts as a link.
'river' is the third definition.
(Amazon is an example)
(Other definitions for amazon that I've seen before include "Strong, aggressive woman" , "Aggressive female" , "Female warrior - parrot - South American river" , "Fighting woman from a great river" , "Net giant" .)