Real Dictionary

yogurt
variable noun: Yogurt is a food in the form of a thick, slightly sour liquid that is made by adding bacteria to milk. A yogurt is a small pot of yogurt.

yogurt in American English
a thick, semisolid food made from milk fermented by a bacterium ( Lactobacillus bulgaricus): it is now often prepared with various flavors
noun: a prepared food having the consistency of custard, made from milk curdled by the action of cultures, sometimes sweetened or flavored

yogurt in British English
noun: a thick custard-like food prepared from milk that has been curdled by bacteria, often sweetened and flavoured with fruit, chocolate, etc