Old Irish súil

← Breton heol (cognate)

← Proto-Celtic *sūle (inherited)

← Proto-Celtic *sūlos (mention)

← Proto-Celtic *sāwol (mention)

← Welsh haul (cognate)

← Proto-Indo-European *sóh₂wl̥ (inherited)

← Primitive Irish *sūli (inherited)

→ Welsh haul (cognate)

→ Irish súil (inherited)

→ Scottish Gaelic sùil (inherited)

→ Manx sooill (inherited)