\Plane\, v. i.
Of a boat, to lift more or less out of the water while in
motion, after the manner of a hydroplane; to hydroplane.

\Plane\, n. [F., fr. L. platanus, Gr. ?, fr. ? broad; --
so called on account of its broad leaves and spreading form.
See {Place}, and cf. {Platane}, {Plantain} the tree.] (Bot.)
Any tree of the genus Platanus.
Note: The Oriental plane ({Platanus orientalis}) is a native
      of Asia. It rises with a straight, smooth, branching
      stem to a great height, with palmated leaves, and long
      pendulous peduncles, sustaining several heads of small
      close-sitting flowers. The seeds are downy, and
      collected into round, rough, hard balls. The Occidental
      plane ({Platanus occidentalis}), which grows to a great
      height, is a native of North America, where it is
      popularly called {sycamore}, {buttonwood}, and
      {buttonball}, names also applied to the California
      species ({Platanus racemosa}).

\Plane\, a. [L. planus: cf. F. plan. See {Plan}, a.]
Without elevations or depressions; even; level; flat; lying
in, or constituting, a plane; as, a plane surface.
Note: In science, this word (instead of plain) is almost
      exclusively used to designate a flat or level surface.
{Plane angle}, the angle included between two straight lines
   in a plane.
{Plane chart}, {Plane curve}. See under {Chart} and {Curve}.
{Plane figure}, a figure all points of which lie in the same
   plane. If bounded by straight lines it is a rectilinear
   plane figure, if by curved lines it is a curvilinear plane
   figure.
{Plane geometry}, that part of geometry which treats of the
   relations and properties of plane figures.
{Plane problem}, a problem which can be solved geometrically
   by the aid of the right line and circle only.
{Plane sailing} (Naut.), the method of computing a ship's
   place and course on the supposition that the earth's
   surface is a plane.
{Plane scale} (Naut.), a scale for the use of navigators, on
   which are graduated chords, sines, tangents, secants,
   rhumbs, geographical miles, etc.
{Plane surveying}, surveying in which the curvature of the
   earth is disregarded; ordinary field and topographical
   surveying of tracts of moderate extent.
{Plane table}, an instrument used for plotting the lines of a
   survey on paper in the field.
{Plane trigonometry}, the branch of trigonometry in which its
   principles are applied to plane triangles.

\Plane\, n. [F. plane, L. plana. See {Plane}, v. & a.]
1. (Geom.) A surface, real or imaginary, in which, if any two
   points are taken, the straight line which joins them lies
   wholly in that surface; or a surface, any section of which
   by a like surface is a straight line; a surface without
   curvature.
2. (Astron.) An ideal surface, conceived as coinciding with,
   or containing, some designated astronomical line, circle,
   or other curve; as, the plane of an orbit; the plane of
   the ecliptic, or of the equator.
3. (Mech.) A block or plate having a perfectly flat surface,
   used as a standard of flatness; a surface plate.
4. (Joinery) A tool for smoothing boards or other surfaces of
   wood, for forming moldings, etc. It consists of a
   smooth-soled stock, usually of wood, from the under side
   or face of which projects slightly the steel cutting edge
   of a chisel, called the iron, which inclines backward,
   with an apperture in front for the escape of shavings; as,
   the jack plane; the smoothing plane; the molding plane,
   etc.
{Objective plane} (Surv.), the horizontal plane upon which
   the object which is to be delineated, or whose place is to
   be determined, is supposed to stand.
{Perspective plane}. See {Perspective}.
{Plane at infinity} (Geom.), a plane in which points
   infinitely distant are conceived as situated.
{Plane iron}, the cutting chisel of a joiner's plane.
{Plane of polarization}. (Opt.) See {Polarization}.
{Plane of projection}.
   (a) The plane on which the projection is made,
       corresponding to the perspective plane in perspective;
       -- called also principal plane.
   (b) (Descriptive Geom.) One of the planes to which points
       are referred for the purpose of determining their
       relative position in space.
{Plane of refraction} or {reflection} (Opt.), the plane in
   which lie both the incident ray and the refracted or
   reflected ray.

\Plane\, v. t. [imp. & p. p. {Planed}; p. pr. & vb. n.
{Planing}.] [Cf. F. planer, L. planare, fr. planus. See
{Plane}, a., {Plain}, a., and cf. {Planish}.]
1. To make smooth; to level; to pare off the inequalities of
   the surface of, as of a board or other piece of wood, by
   the use of a plane; as, to plane a plank.
2. To efface or remove.
         He planed away the names . . . written on his
         tables.                               --Chaucer.
3. Figuratively, to make plain or smooth. [R.]
         What student came but that you planed her path.
                                               --Tennyson.