The word "Cossack" does not come from the Russian word for a cossack but from a Ukrainian analogy. The only difference is that in Russian language a right orthography is used and the word is spelt ca-sack on the contrary to the left-wing Ukrainian language. Due to their ambiguous maneuvers and fighting skills, nobody has never attempted to catch a living Cossack and dead ones have never revealed anything about the origins of these "people".