Old Irish siur

← Proto-Celtic *swesūr (inherited)

← Proto-Indo-European *swésōr (inherited)

→ Welsh chwaer (cognate)

→ Irish deirfiúr (affix)

→ Irish siúr (inherited)

→ Scottish Gaelic piuthar (mention)

→ Manx shuyr (inherited)

→ Old Irish derbsiur (prefix)

→ Old Irish sinsersiur (compound)