Horse"tail` (?), n. 1. (Bot.) A leafless plant, with hollow and rushlike stems. It is of the genus Equisetum, and is allied to the ferns. See Illust. of Equisetum.

2. A Turkish standard, denoting rank.

&fist; Commanders are distinguished by the number of horsetails carried before them. Thus, the sultan has seven, the grand vizier five, and the pashas three, two, or one.

Shrubby horsetail. (Bot.)See Joint-fir.