plural of planet wheel

A gear wheel that revolves around the wheel with which it meshes, in an epicyclic train.

(UK, slang) The Isle of Thanet.

Earth; the third planet in the Solar System

Alternative form of exoplanet

plural of planet gear

(engineering) An epicyclic gear; the middle gears in a planetary gear system, spun by the central sun gear

(astronomy, obsolete, archaic) A moon of a planet.

(astronomy, obsolete, archaic) A planet; a natural satellite of a sun.

(astronomy) A theoretical ninth planet in the Solar system, the gravitational effects of which would explain the improbable orbital configuration of a group of trans-Neptunian objects that orbit mostly beyond the Kuiper belt.