plane

Etymology 1

From Latin plānum (“flat surface”), a noun use of the neuter of plānus (“plain”). The word was introduced in the 17th century to distinguish the geometrical senses from the other senses of plain. Doublet of llano, piano, and plain.

adj

1. Of a surface: flat or level.

noun

1. A level or flat surface.
2. (geometry) A flat surface extending infinitely in all directions (e.g. horizontal or vertical plane).
   Mirrors in the compartments have been canted out of the vertical plane to reduce reflections to the passengers when seated. 1979 August, Graham Burtenshaw, Michael S. Welch, “O.V.S. Bulleid's SR loco-hauled coaches - 1”, in Railway World, page 396
   1. (anatomy) An imaginary plane which divides the body into two portions.
3. A level of existence or development.
   astral plane
4. A roughly flat, thin, often moveable structure used to create lateral force by the flow of air or water over its surface, found on aircraft, submarines, etc. (Compare wing, airfoil, hydrofoil.)
5. (computing, Unicode) Any of 17 designated ranges of 2¹⁶ (65,536) sequential code points each.

Etymology 2

From Middle English plane, plaine, from Anglo-Norman plaine, from Late Latin plāna (“planing tool”).

noun

1. (countable, carpentry) A tool for smoothing wood by removing thin layers from the surface.

verb

1. (transitive, carpentry) To smooth (wood) with a plane.

Etymology 3

Clipping of aeroplane.

noun

1. An airplane; an aeroplane.
   The plane is travelling impossibly slowly – 30km an hour – when it gently noses up and leaves the ground. With air beneath them, the rangy wings seem to gain strength; the fuselage that on the ground seemed flimsy becomes elegant, like a crane vaunting in flight. It seems not to fly, though, so much as float. 2013-09-06, Tom Cheshire, “Solar-powered travel”, in The Guardian Weekly, volume 189, number 13, page 34
2. (entomology) Any of various nymphalid butterflies, of various genera, having a slow gliding flight.
3. (entomology) The butterfly Bindahara phocides, family Lycaenidae, of Asia and Australasia.

verb

1. (nautical, of a boat) To move in a way that lifts the bow out of the water.
2. To glide or soar.

Etymology 4

From Middle English plane, borrowed from Old French plane, from Latin platanus, from Ancient Greek πλάτανος (plátanos), from πλατύς (platús, “wide, broad”).

noun

1. (countable) A deciduous tree of the genus Platanus.
2. (Northern UK) A sycamore.