planum

From Latin plānum.

planum

1. (astronomy, planetology, planetography, astrogeography, astrogeology) an elevated plain or plateau on a moon or planet

From Latin plānum (“level ground, plain”).

planum (plural plana)

1. (anatomy) any flat surface

• planum temporale

• unpalm

From plānus (“flat, even, level”).

• (Classical Latin) IPA^(key): [ˈpɫaː.nũː]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈplaː.num]

plānum n (genitive plānī); second declension

1. a plain, level ground

Second-declension noun (neuter).

• van der Sijs, Nicoline, editor (2010), “plein”, in Etymologiebank, Meertens Institute
• “planum”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• "planum", in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• planum in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• Carl Meißner, Henry William Auden (1894) Latin Phrase-Book‎^[1], London: Macmillan and Co.
  • to demonstrate, make a thing clear: aliquid planum facere (Ad Herenn. 2. 5)