Proto-Celtic *īsarnom

→ English iron (derived)

→ Afrikaans yster (derived)

→ Breton houarn (inherited)

→ Welsh haearn (inherited)

→ Danish jern (derived)

→ Middle English iren (derived)

→ Irish iarann (inherited)

→ Scottish Gaelic iarann (inherited)

→ Gothic 𐌴𐌹𐍃𐌰𐍂𐌽 (derived)

→ Manx yiarn (inherited)

→ Limburgish iezer (derived)

→ Marshallese aen (derived)

→ Mòcheno aisn (derived)

→ Dutch ijzer (derived)

→ Old Irish íarn (inherited)

→ Swedish järn (derived)

→ Middle Welsh haearn (inherited)