a tart-tasting drink originally of the Caucasus, made from cow's or sometimes goat's milk to which the bacteria Streptococcus and Lactobacillus have been added.
Origin: 1880–85; < Russiankefír, apparently < a Caucasian language; compare Ossetic kʾæpy, kʾæpu kefir, Mingrelian kipuri milk curdled in an animal skin