Attested early 18th century in correspondence regarding Russia's purchase of weapons from Western Europe. The etymology is uncertain; there are several hypotheses.
Šanskij, N. M. (2004) “кортик”, inŠkolʹnyj etimologičeskij slovarʹ russkovo jazyka [School Etymological Dictionary of the Russian Language] (in Russian), Moscow: Drofa
Vasmer, Max (1964–1973) “кортик”, inOleg Trubachyov, transl.,Этимологический словарь русского языка [Etymological Dictionary of the Russian Language] (in Russian), Moscow: Progress