Sources of the name "orc"
In Beowulf, ll: 112,the zombie-like Grendel's race is described as Orc-néas, which seems to mean "corpses of Orcus." Orcus, in Roman mythology, was an alternative name for Pluto, Hades, or Dis Pater, god of the land of the dead. The name "Orcus" seems to have been given to his evil and punishing side, as the god who tormented evildoers in the afterlife. Like the name Hades (or the Northern Hel, for that matter), "Orcus" could also mean the land of the dead. Tolkien derived his 'Orcs' from this passage in Beowulf. (See below.)
However, the word "orc" had long existed in English as the name of a type of sea monster. This derives ultimately from Pliny the Elder's description of the orca, modulated through the long tradition of Medieval Bestiaries. In his Natural History, Pliny described a creature that was "so monstrous and aggressive a whale, that no words are adequate to describe it, except as a huge mass of flesh armed with menacing teeth." Historia Naturalis 9.v.12
According to one medieval source, Charlemagne encountered and destroyed an orc that attacked his ship in the Mediterranean. In Orlando Furioso, an epic by Ludovico Ariosto, the name of "orc" was given to a sea monster that captured the damsel Angelica, and was fought by the hero Rogero riding a hippogriff. This orc was huge, scaly, tusked, pig-nosed, and bristled.
A land-dwelling orc also appears in Orlando Furioso, XVII: 29. This "land orc" is a blind giant with a long nose and tusks jutting out like a savage swine. The land orc is a cannibal who holds king Norandino and his men captive in a cave. The story is reminiscent of the tale of Polyphemus. It should be noted that, in Italian, "orca" means a killer whale while "orco" means an ogre, a humanoid creature.
From this usage, the word "orc" made it into English by being used by Michael Drayton in his Polyolbion, an epic poem about Brutus the Trojan and the mythical founders of Britain, and also appears in the epic poem Paradise Lost, by John Milton.
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