Old Irish sin

← Proto-Celtic *sindos (inherited)

← Welsh hyn (cognate)

← Proto-Indo-European *sḗm (inherited)

← Proto-Indo-European *só (mention)

← Old Irish in (mention)

→ Irish sin (inherited)

→ Scottish Gaelic sin (inherited)

→ Manx shen (inherited)

→ Latvian siena (cognate)

→ Middle Irish sin (inherited)

→ Old Irish in (mention)

→ Old Irish sund (mention)

→ Old Irish ísin (affix)

→ Old Irish amein (mention)

→ Old Irish inunn (mention)

→ Old Irish intísin (affix)