Breton houarn

← Proto-Celtic *īsarnom (inherited)

← Welsh haearn (cognate)

← Proto-Indo-European *h₁ésh₂r̥ (derived)

← Old Irish íarn (cognate)

→ Breton houarnek (suffix)

→ Breton marc'h-houarn (compound)

→ Welsh haearn (cognate)

→ Irish iarann (cognate)

→ Scottish Gaelic iarann (cognate)

→ Manx yiarn (cognate)

→ Old Irish íarn (cognate)