Words that come from Proto-Celtic sista-

22 words across 4 languages descend from Proto-Celtic sista- — including seas, sessam, seasamh, shassoo, so-hassoo, cohassooaght, cohassooagh, neuhassooagh.

See the etymology of sista- itself →

Irish (10)

Manx (8)

Old Irish (2)

Scottish Gaelic (2)