barm

Etymology 1

From Middle English barm, barme, berm, bearm, from Old English bearm (“lap; bosom”), from Proto-West Germanic *barm, from Proto-Germanic *barmaz (“lap; bosom”), from Proto-Indo-European *bʰer- (“to bear”). Cognate with German Barm (“lap; bosom”).

noun

1. (obsolete outside dialects) bosom, lap.

Etymology 2

From Middle English berme, berm, from Old English beorma, from Proto-West Germanic *bermō (“yeast; barm”); related to the dialectal Low German Bärm (“yeast”), from Middle Low German barm, berm. The cake sense is possibly a shortened form of barmcake, which would be made with yeast as described in that sense, or possibly it is from the Irish bairín breac, a type of bread.

noun

1. Foam rising upon beer or other malt liquors when fermenting, used as leaven in brewing and making bread; yeast.
   In 1577 yeast, called barm, is bought at 9d. the pail. 1882, James Edwin Thorold Rogers, A History of Agriculture and Prices in England, volume 4, page 620
2. A small, round, flat individual loaf or roll of bread.

Etymology 3

From Middle English bermen, from the noun (see above).

verb

1. To spurge; foam