köken: Borrowed from Old Church Slavonic оубиица (ubiica), from Proto-Slavic *ubьjьca. In case of native origin *убе́йца (*ubéjca) would be expected. By surface analysis, уби́ть (ubítʹ) + -ца (-ca). Compare Russian уби́вец (ubívec), уби́вца (ubívca) (dialectal) and Ukrainian уби́вця (ubývcja).