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 dre ed.— 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 bra work: a workman who planishes, esp. one who prepares copper-plates for engravers; Plan′i sphere , a sphere projected on a plane.— adjs. Plan isp her′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. plan us , plain.]