(astronomy) The orbital plane passing through a planetary system's barycenter (center of mass) perpendicular to its angular momentum vector.

A mirror with a flat surface (i.e. the surface is a single plane)

An aircraft used for surveillance.

(differential geometry) Given a point P on a surface M, the tangent plane of M at point P, denoted by T_P(M), is the plane passing through P which contains the tangent lines of all the curves on M passing through P.

(aircraft, military) A military aircraft primarily designed to attack enemy aircraft. Frequently shortened to fighter.

(mathematics, astronomy) The mean plane occupied by the orbit of a satellite during a precession cycle; the plane normal to the orbital precession pole of the satellite.

A plane which declines from the zenith, or inclines toward the horizon.

(anatomy) the plane which divides the body of an animal into similar right and left halves

An airplane that supposedly could detect oil fields underground.

(mechanics) One of the simple machines; a sloping surface such as a ramp such that an object can be raised with less effort than being lifted vertically.