One whose duty consisted in citing delinquents to the ecclesiastical courts; an apparitor; literally, a summoner.

“Sim Somnor, in hast, wend thou thi way,

Byd Joseph and his wyff, be name,

At the coort to apper this day,

Hem to pourge of her defame.”

Coventry Mysteries.

Chaucer gives us a description of the Sompnour in his Canterbury Tales.

Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.