From a common Semitic source; compare Arabic مصر (Miṣr) and Ugaritic msrm [script?]. The ending is the standard dual form, perhaps related to the ancient conceptualization of Egypt as two realms: Upper Egypt and Lower Egypt. Connections have also been drawn to Hebrew מיצר (meitsár, “sea strait”).
מִצְרַיִם f (Biblical Hebrew pausal form מִצְרָיִם)
מצרים • (Mitsroim) ?