(especially in czarist Russia) a person belonging to any of certain groups of Slavs living chiefly in the southern part of Russia in Europe and forming an elite corps of horsemen.
Origin: 1590–1600; < Polishkozak or Ukrainiankozák, ultimately < a Turkic word taken to mean “adventurer, freebooter,” adopted as an ethnic name by Turkic tribal groups of the Eurasian steppes
(formerly) any of the free warrior-peasants of chiefly East Slavonic descent who lived in communes, esp in Ukraine, and served as cavalry under the tsars
—adj
2.
of, relating to, or characteristic of the Cossacks: a Cossack dance
[C16: from Russian kazak vagabond, of Turkic origin]
a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.
a fool or simpleton; ninny.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.
1598, from Rus. kozak, from Turk. quzzak "adventurer, guerilla, nomad," from qaz "to wander." The same Turkic root is the source of the people-name Kazakh and the nation of Kazakhstan.