Middle Irish sínid

← Proto-Celtic *sīnīti (inherited)

← Proto-Celtic *sīros (mention)

← Welsh hir (cognate)

← Gothic 𐍃𐌴𐌹𐌸𐌿𐍃 (cognate)

← Proto-Indo-European *seh₁- (inherited)

← Latin sērus (cognate)

← Sanskrit साय (cognate)

← Old Irish sír (cognate)

→ Irish sín (inherited)

→ Manx sheeyn (inherited)