Casimir is a Latin version of the Polish male name Kazimierz (Polish pronunciation: [ka'ʑi.mjeʂ]).
The original Polish feminine form is Kazimiera, in Latin and other languages rendered as Casimira.
[1] There is some debate as to the origin of the prefix, as it could be from the Polish "kazac" (meaning "to preach") but is more commonly cited as coming from "kaziti" (meaning "to destroy"), with "miru" meaning "peace".
[2][3][4][5] Old Polish and dialectal Polish versions are Kaźmierz and Kaźmir.
Diminutive; Kazik, Kaziuk, Kaziu, Ziuk etc.