plane

A level or flat surface.

A flat surface extending infinitely in all directions (e.g. horizontal or vertical plane).

A level of existence or development. (eg, astral plane)

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.

(Unicode) Any of a number of designated ranges of sequential code points.

An imaginary plane which divides the body into two portions.