Definition of "orc"

Who at one stroke didst pare away three heads from off the shoulders of an Orke, begotten by an Incubus.

1656, Samuel Holland, Don Zara del Fogo, I.1

The chief exploit of the hero, Beowulf the Great, is the destruction of the two monsters Grendel and his mother; both like most of the evil beings in the old times, dwellers in the fens and the waters; and both, moreover, as some Christian bard has taken care to inform us, of "Cain's kin," as were also the eotens, and the elves, and the orcs (eótenas, and ylfe, and orcneas).

1834, "The National Fairy Mythology of England" in Fraser's Magazine for Town and Country, Vol. 10, p. 53

There was a flash like flame and the helm burst asunder. The orc fell with cloven head.

1954, JRR Tolkien, The Fellowship of the Ring

Ukranians themselves, including those on the right, preferred to call the events the 'Revolution of Dignity', depicted not in terms of ethnicity or class, but in simple civic black and white – a revolution of the people against Yanukovych's 'Mordor' and his 'Orcs'.

2015, Andrew Wilson, The Ukrainians: Unexpected Nation, page 354

And now we must watch the old world go up in flames, in the mad spectacle of Putin’s orcs descending upon Kyiv to execute his macabre plan.

2022 March 1, Bruno Maçães, “Europe’s Illusion of Peace Has Been Irrevocably Shattered”, in Time

Plenty of Belarusian exiles have gone to Europe, but if you run West, then the Orcs [a Ukrainian slang term for "Russian soldiers"] will just follow you there. It's better to risk your life as a free person than to keep running.

2022 July 25, Michael Wasiura, “Belarusian Exiles Join Ukrainians in Taking Up Arms Against Russia”, in Newsweek‎, retrieved 2022-07-25