1

yeast

play
noun \ ˈyēst , especially Southern and Midland US ˈēst \

Definition of yeast

1 a :a yellowish surface froth or sediment that occurs especially in saccharine liquids (such as fruit juices) in which it promotes alcoholic fermentation, consists largely of cells of a fungus (such as the saccharomyces, Saccharomyces cerevisiae), and is used especially in the making of alcoholic liquors and as a leaven in baking
b :a commercial product containing yeast fungi in a moist or dry medium
c (1) :a unicellular fungus that is present and functionally active in yeast, usually has little or no mycelium, and reproduces by budding
(2) :any of various similar fungi
2 archaic :the foam or spume of waves
3 :something that causes ferment or activity
  • were all seething with the yeast of revolt
  • —J. F. Dobie

yeast-like

or less commonly yeastlike play \ˈyēst-ˌlīk, especially Southern and Midland US ˈēst-\ adjective

Examples of yeast in a Sentence

  1. taxation without representation proved to be the yeast of rebellion

Recent Examples of yeast from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'yeast.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of yeast

Middle English yest, from Old English gist; akin to Old High German jesen, gesen to ferment, Greek zein to boil


2

yeast

verb

Definition of yeast

intransitive verb

Recent Examples of yeast from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'yeast.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of yeast

1819

Other Biochemistry Terms


YEAST Defined for English Language Learners

yeast

play
noun

Definition of yeast for English Language Learners

  • : a type of fungus that is used in making alcoholic drinks (such as beer and wine) and in baking to help make dough rise


YEAST Defined for Kids

yeast

play
noun \ ˈyēst \

Definition of yeast for Students

1 :a single-celled fungus that ferments sugar to produce alcohol and carbon dioxide
2 :a commercial product containing living yeast cells that is used in baking to make dough rise and in the making of alcoholic beverages (as wine)

Medical Dictionary

yeast

play
noun \ ˈyēst \

medical Definition of yeast

1 :a unicellular chiefly ascomycetous fungus (as of the family Saccharomycetaceae) that has usually little or no mycelium, that typically reproduces asexually by budding, and that includes forms (as Saccharomyces cerevisiae) which cause alcoholic fermentation and are used especially in the making of alcoholic beverages and leavened bread
2 :a yellowish surface froth or sediment that occurs especially in sugary fermenting liquids (as fruit juices) and consists chiefly of yeast cells and carbon dioxide
3 :a commercial product containing yeast cells in a moist or dry medium

yeastlike

play \-ˌlīk\ adjective


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