(mathematics) A topological space homeomorphic to a plane (or open disk) and equipped with a hyperbolic metric.

A plane located halfway between the suprasternal notch and the upper border of the symphysis pubis; this indicates the margin of the transpyloric plane, which in most cases cuts through the pylorus, the tips of the ninth costal cartilages and the lower border of the first lumbar vertebra.

plural of bit plane

(set theory) The Cartesian product of two real lines.

plural of datum plane

(engineering) A plane which serves as a reference or base for the measurement of other quantities.

plural of paper plane

(nautical) A technique for navigation using planar geometry. / (nautical, proscribed) A technique for navigation using the assumption the Earth is flat.

(anatomy) Any vertical plane that divides the body into anterior and posterior (belly and back) sections.

A general-purpose bench plane, used for general sizing of wood and for smoothing or straightening edges.