from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A creamy drink made of fermented cow's milk.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A fermented milk drink from the Caucasus and Eastern Europe.
from the GNU version of the Collaborative International Dictionary of English
- n. An effervescent liquor like kumiss, made from fermented milk, used as a food and as a medicine in the northern Caucasus.
- n. A sour fermented milk drink, used in various regions of Asia, made by addition of Streptococcus or Lactobacillus cultures to cow's or goat's milk; it is considered by some as a form of yoghurt.
from The Century Dictionary and Cyclopedia
- n. An effervescent drink prepared from the fermented milk of cows: used by the natives of the northern Caucasus region, and now extensively used elsewhere as a food for. invalids. It contains from 1 to 2 per cent. of free lactic acid and from 1 to 3 per cent. of alcohol. The original ferment used is a particular fungus called kefir grains (which see).
Russian, probably ultimately from Old Turkic köpür, (milk) froth, foam, from köpürmäk, to froth, foam.(American Heritage® Dictionary of the English Language, Fourth Edition)
From North-Caucasian languages via Russian кефир (kefír). (Wiktionary)