yeast

1. An often humid, yellowish froth produced by fermenting malt worts, and used to brew beer, leaven bread, and also used in certain medicines. (countable, uncountable)
2. A single-celled fungus of any of a wide variety of taxonomic families. (countable, uncountable)
3. Baker's yeast (Saccharomyces cerevisiae) (countable, uncountable)
4. A compressed cake or dried granules of this substance used for mixing with flour to make bread dough rise. (countable, uncountable)
5. brewer's yeast, certain species of Saccharomyces, principally Saccharomyces cerevisiae and Saccharomyces carlsbergensis. (countable, uncountable)
6. Candida, a ubiquitous fungus that can cause various kinds of infections in humans. (countable, uncountable)
7. The resulting infection, candidiasis. (countable, uncountable)
8. A frothy foam. (countable, figuratively, uncountable)

Plural yeasts