noun

1. 1. a flat-based, single-pointed solid formed by a rotating straight line that traces out a closed-curved base from a fixed vertex point that is not in the same plane as the base; esp., one (right circular cone) formed by tracing a circle from a vertex perpendicular to the center of the base (also formed by rotating a right triangle 360° with either leg as the axis, or by rotating an isosceles triangle 360° with the altitude as the axis)
   2. the surface of such a solid
   3. a similar unbounded surface extending outward in both directions from a point: it is formed by rotating in an elliptical or circular pattern a straight line that always passes through this point
2. any object or mass shaped like a cone; specif.,
   1. a crisp shell of pastry for holding a scoop of ice cream
   2. the peak of a volcano
   3. any of various machine parts
3. Bot.
   1. a reproductive structure of certain nonflowering plants, consisting of an elongated central axis upon which are borne overlapping scales, bracts, sporophylls, etc., usually in a spiral fashion, and in which are produced pollen, spores, or ovules; strobilus: cones are found in cycads, conifers, club mosses, horsetails, etc.
   2. any similar structure, as the catkin of hops
4. Zool.
   1. any of the flask-shaped cells in the retina of most vertebrates, sensitive to bright light and color
   2. cone shell
5. the diaphragm (sense ) of a speaker, usually cone-shaped

Etymology: ME < L conus < Gr kōnos, a wedge, peak, cone < IE base kō(n)-, to sharpen > hone, L cos

transitive verb coned, coning con′·ing