Where does “ים סוף” come from?

ים סוף (Hebrew) comes from Hebrew סוף, from Late Egyptian ṯwfj — papyrus; papyrus thicket.

Ancestry of “ים סוף”, step by step

ים סוף traces back through two separate lines of ancestry.

via Hebrew סוף

StepLanguageWordMeaning
1HebrewסוףAn end, a finish; reed, bulrush, papyrus
2Late Egyptianṯwfjpapyrus; papyrus thicket

via Hebrew ים

StepLanguageWordMeaning
1Hebrewיםsea, ocean; west; a lot
Every word from Late Egyptian ṯwfj →Every word from Hebrew סוף →