from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Roman Mythology The god of the dead and the ruler of the underworld.
  • n. A dwarf planet that until 2006 was classified as the ninth planet in our solar sytem, having a sidereal period of revolution about the sun of 248.5 years, 4.4 billion kilometers (2.8 billion miles) distant at perihelion and 7.4 billion kilometers (4.6 billion miles) at aphelion, and a diameter less than half that of Earth. See Usage Note at planet.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • proper n. Greek and Roman god of the underworld.
  • proper n. Originally known as the ninth planet but reclassified in 2006 as a dwarf planet, the brightest and first known Kuiper belt object, represented by the symbol ♇ in astronomy and in astrology.

from the GNU version of the Collaborative International Dictionary of English

  • The son of Saturn and Rhea, brother of Jupiter and Neptune; the dark and gloomy god of the Lower World.
  • The ninth planet of the Solar System, the smallest (5700 km radius) and most distant from the sun. The suggestion has been made that it more closely resembles a large close comet than a planet. Its orbit has an eccentricity of 0.248, larger than that of any other planet; it varies from 4.44 to 7.37 billion km distance from the sun.

from The Century Dictionary and Cyclopedia

  • n. In Roman mythology, the lord of the infernal regions, son of Saturn and brother of Jupiter and Neptune.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a small planet and the farthest known planet from the sun; it has the most elliptical orbit of all the planets
  • n. a cartoon character created by Walt Disney
  • n. (Greek mythology) the god of the underworld in ancient mythology; brother of Zeus and husband of Persephone


from The American Heritage® Dictionary of the English Language, 4th Edition

Latin Plūtō, Plūtōn-, from Greek Ploutōn, from ploutos, wealth (from the belief that the underworld was the source of wealth from the ground).

from Wiktionary, Creative Commons Attribution/Share-Alike License

Ancient Greek Πλούτων (Plutōn)


  • "To "pluto" is "to demote or devalue someone or something" much like what happened to the former planet last year when the General Assembly of the International Astronomical Union decided Pluto didn't meet its definition of a planet."

    NASA Watch: Space Science News: January 2007 Archives

  • You are arguing my point that radioactive decay in all planets should be about the same (Order of magnitude, within a couple of degrees) If pluto is heated by Radioactive decays to 40K and the Earth is at 288K, either the Earth does not recieve MOST of it’s heat from radioactive decay, or the Eearth has many times, (not 2 or 3 % but 700% or 800%) the radioactive material that Pluto has.

    Hits « Climate Audit

  • Showalter, on the other hand, doesn't think it matters what you call Pluto. Top Stories

  • In an e-mail interview with, Stern lays out the case for Pluto's planethood and explains why it matters what we call Pluto and other objects in the solar system.

    Yahoo! News: Business - Opinion

  • The furthest planet in our solar system, Neptune, orbits at an average of 30 AU from the Sun. The Kuiper Belt, populated with icy bodies such as Pluto, is at roughly 50 AU from the Sun.

    Archive 2008-12-11

  • She wore blue mechanic’s coveralls that had the name Pluto stitched across the breast pocket.

    The Gin Closet

  • I think Pluto is up there with the great comics in the West, like MAUS and WATCHMEN.

    *Pluto: Urasawa x Tezuka Book 8 — Recommended » Manga Worth Reading

  • New Horizons/Pluto is a good example how a budget and a deadline came together under Dr. Stern as the Principal Investigator and was conveived and executed in the FBC times.

    The Force Is Strong With This One - NASA Watch

  • And for some reason, I after a short pause, said, ‘Why not call it Pluto?’

    R.I.P.: the girl who named Pluto

  • When last I trained my home telescope on the unsuspecting Jeff, the year was 1969, Mrs. Sklenkar was our fifth grade teacher, and Pluto's shame was years away although Mike Brown, the astronomer who put the first nail in Pluto's coffin and recently authored of How I Killed Pluto and Why it Had it Coming, continues to receive daily hate mail and from people he calls "Pluto huggers".

    Carolyn Bucior: The Fabric of My Cosmos


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  • Or is it a pla(y)net? ...depending upon whose court system Pluto is in?

    March 3, 2013

  • I still consider Pluto a planet.

    March 3, 2013