Atter
Atter (Old English: āttor; cf. Old Norse: eitr) is an archaic, and poetic, term for poisonous bodily fluid, especially venom of a venomous animal, such as a snake, dragon or other reptile, but also other vile, corrupt or morbid substance from the body, such as pus from a sore or wound, as well as bitter substance, such as bile.