koumiss vs kumis

koumiss and kumis both are nouns.

Word	Noun	Adjective	Verb	Adverb
koumiss	Yes	No	No	No
kumis	Yes	No	No	No

As nouns, koumiss and kumis are synonyms defined as:

koumiss and kumis: an alcoholic beverage made from fermented mare's milk; made originally by nomads of central Asia

koumiss (noun)	kumis (noun)
an alcoholic beverage made from fermented mare's milk; made originally by nomads of central Asia	an alcoholic beverage made from fermented mare's milk; made originally by nomads of central Asia