Emily Dickinson Lexicon

HY'DA-TID, or HY'DA-TIS, n. [Gr. υδατις, from υδωρ, water.]

A little transparent vesicle or bladder filled with water, on any part of the body, as in dropsy. Quincy. Darwin. Hydatids are certain spherical bodies, found occasionally in man, as well as in other animals, lodged in or adhering to the different viscera. Some of them, at least, are considered as possessing an independent vitality, and as constituting a distinct animal, allied to the æni or tape-worm. They consist of a head, neck, and vesicular body filled with a transparent fluid. Cyc. Parr.