The foam, or troth (top yeast), or the sediment (bottom yeast), of beer or other in fermentation, which contains the yeast plant or its spores, and under certain conditions produces fermentation in saccharine or farinaceous substances; a preparation used for raising dough for bread or cakes, and making it light and puffy; barm; ferment.
Spume, or foam, of water.
A form of fungus which grows as indvidual rounded cells, rather than in a mycelium, and reproduces by budding; esp. members of the orders Endomycetales and Moniliales. Some fungi may grow both as a yeast or as a mycelium, depending on the conditions of growth.
Enthusiasm is the yeast that makes your hopes shine to the stars. Enthusiasm is the sparkle in your eyes, the swing in your gait. The grip of your hand, the irresistible surge of will and energy to execute your ideas. Henry Ford
You know how you wake up in the morning and sometimes you look gorgeous and other times you look like you got hit by a mack truck? I realized that my mack truck is food. If I have no sugar, yeast or wine, I have no undereye bags and my skin is perfect. Mariska Hargitay
Given the opportunity, under the right conditions, two cells from wildly different sources, a yeast cell, say, and a chicken erythrocyte, will touch, fuse, and the two nuclei will then fuse as well, and the new hybrid cell will now divide into monstrous progeny. Naked cells, lacking self-respect, do not seem to have any sense of self. Lewis Thomas
You can't just leave out one part; the bread won't rise if the yeast isn't there. Holly Near