Plane

Plane, plān, n. (geom.) a surface on which, if any two points be taken, the straight line joining them will lie entirely on the surface: (astron.) a surface thought of as bounded by the line round which a heavenly body moves: any flat or level surface: any incline on which coal is lowered by the effect of gravity: any grade of life or of development.—adj. having the character of a plane: pertaining to, lying in, or forming a plane.—v.t. to make plane or smooth.—adj. Plā′nary, relating to a plane: flat.—n. Plane′-tā′ble, a topographical instrument used in field-mapping, and having a sighting-telescope for observing objects, whose angles may be noted on a paper on the table of the instrument: an inclined table on which ore is dressed.—v.t. to survey with a plane-table.—ns. Plan′igraph, an instrument for reducing or enlarging drawings; Planim′eter, an instrument for measuring the area of a plane figure.—adjs. Planimet′ric, -al.—n. Planim′etry, the mensuration of plane surfaces.—adj. Planipet′alous, having flat petals.—ns. Plan′isher, a thin flat-ended tool used for smoothing tin-plate and brasswork: a workman who planishes, esp. one who prepares copper-plates for engravers; Plan′isphere, a sphere projected on a plane.—adjs. Planispher′ic; Plāno-con′cave, plane on one side and concave on the other; Plā′no-con′ical, plane on one side and conical on the other; Plā′no-con′vex, plane on one side and convex on the other.—n. Planog′raphist, a map-maker.—adj. Plā′no-horizon′tal, having a plane horizontal surface or position.—ns. Planom′eter, a plane surface used in machine-making as a gauge for plane surfaces; Planom′etry, the measurement of plane surfaces.—adj. Plā′no-sub′ulate, smooth and awl-shaped.—Plane angle, an angle contained by two straight lines in a plane; Plane figure, a figure all of whose points lie in one plane; Plane geometry, the geometry of plane figures; Plane sailing, the calculation of a ship's place in its course, as if the earth were flat instead of spherical: easy work; Plane trigonometry, that branch of trigonometry which treats of triangles described on a plane.—Inclined plane (see Incline); Perspective plane (see Perspective). [Fr.,—L. planus, plain.]