In Anglo-Saxon England: a man who rules over a large area or a shire, usually subject to the king. Also used as a title placed immediately before (and in Old English also immediately after) a name.
In Anglo-Saxon England, the word, in its widest sense, denotes a nobleman, of lower rank than a king but higher than a thegn, occasionally of royal birth, exercising authority over an identifiable area or people. The precise political implications of the term changed over time.
Old English. Probably cognate with or formed similarly to Old Frisian aldermon head of a district or town, counsellor of an abbot from the Germanic base of alder + the Germanic base of man.