jǫstr

Old Norse

Etymology

From Proto-Germanic *jestuz. Note that the j- in this word is not etymological, but comes from breaking; in Proto-Norse, j- was always lost word-initially. Thus, the development of the nominative has been *jestuʀ > *estuʀ > *eastuʀ > jǫstr, with U-mutation visible.

Noun

jǫstr m (genitive jastar, dative isti)

yeast
Synonym: gerð

Declension

Declension of *jǫstr* (strong u-stem, singular only)
masculine	singular
masculine	indefinite	definite
nominative	jǫstr	jǫstrinn
accusative	jǫst	jǫstinn
dative	isti	istinum
genitive	jastar	jastarins

Related terms

œsa

Descendants

Icelandic: jöstur
Norwegian Nynorsk: jester, jest
Norwegian Bokmål: jest
Old Swedish: iæster
- Swedish: jäst