The Nuttall Encyclopedia
A title of nobility, ranking third in the British peerage; originally election to the dignity of earl carried with it a grant of land held in feudal tenure, the discharge of judicial and administrative duties connected therewith, and was the occasion of a solemn service of investiture. In course of time the title lost its official character, and since the reign of Queen Anne all ceremony of investiture has been dispensed with, the title being conferred by letters-patent. The word is derived from the Anglo-Saxon eorls which signified the "gentle folk," as distinguished from the ceorls , the "churls" or "simple folk."
Wood, James, ed. Entry for 'Earl'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/e/earl.html. Frederick Warne & Co Ltd. London. 1900.