Ēq'ui-sē'tum, n.

n.; pl. ĒQ'UI-SĒ'TĀ. [Lat., from equus, horse, and seta, a thick, stiff hair, bristle.] (Bot.) A genus of leafless plants, with hollow stems, containing much silicious matter, called horse-tail, in allusion to the fine branches of the species E. hyemale, known as the Dutch rush, or scouring rush, which is much used for scouring and polishing wood and metals. Loudon.