Major Settlement in the Parish of Felixkirk
- Trillebi(a), Trylleby 1189,1248 Riev 1226 FF 1252 Ch 1285 KI
- Thirleby 1271 Ch 1316 Vill 1399 YI 1579 FF
- Thrilleby 1273 Riev 1301 LS
The forms point to an ON Þrilli or Þrylli . No such name is on record, but it is a conceivable weak diminutive of the pers. name element þrýð - found in ON Þrýð -rikr . If so, the name means 'Þrylli 's by.'