- barm (n.)
- Old English beorma "yeast, leaven," also "head of a beer," from Proto-Germanic *bermon- (source also of Dutch berm, Middle Low German barm), from PIE root *bher- (4) "to cook, bake" (source also of Latin fermentum "substance causing fermentation," Sanskrit bhurati "moves convulsively, quivers," Middle Irish berbaim "I boil, seethe;" see brew (v.)).
