Emily Dickinson Lexicon

BUT'TER-WORT, n.

A species of Pinguicula, a plant growing on bogs or soft grounds. The leaves are covered with soft pellucid prickles, which secrete a glutinous liquor; and milk, in which these are steeped, or washed, acquires, in a day or two, consistency, and is an agreeable food, used in the north of Sweden. – Encyc.