- a horse's tail
Origin of horsetaildescriptive any of the only surviving genus (Equisetum) of a division (Equisetophyta) of plants having hollow, jointed stems, with scalelike leaves at the joints and spores borne in terminal cones; scouring rush
- Any of various simple vascular plants, of the family Equisetaceae, that have hollow stems and produce spores.
- A Turkish standard denoting rank.
- Commanders were distinguished by the number of horsetails carried before them. The sultan had seven, the grand vizier five, and the pashas three, two, or one.