yogurt /yō″gərt/ [Turk, yoghurt] , a slightly acid, semisolid, curdled milk preparation made from either whole or skimmed cow’s milk and milk solids by fermentation with organisms from the genus Lactobacillus. It is rich in B complex vitamins and a good source of protein. It also provides a medium in the GI tract that retards the growth of harmful bacteria and aids in mineral absorption. Also spelled yoghurt.