Asian animal, not European, is seen in river (6)
I believe the answer is:
tigris
'river' is the definition.
(I know that Tigris is a river)
'asian animal not european is' is the wordplay.
I cannot really understand how this works, but
'is' is found in the answer.
This explanation may well be incorrect...
'seen in' is the link.
Can you help me to learn more?
(Other definitions for tigris that I've seen before include "Tributary of the Euphrates River" , "flower of Iraq" , "River of Turkey/Iraq" , "River of Baghdad" , "Major tributary of the Euphrates" .)