Latin collective of comes, comitem "a companion, an associate" (see count (n.)).
Online Etymology Dictionary, © 2010 Douglas Harper
Examples from the Web for comitatus
In principle we may regard him as the princeps of a comitatus.The Heroic Age
H. Munro Chadwick
The institution of the comitatus in its first state had nothing whatever to do with the holding of land.The Growth of the English Constitution
Edward A. Freeman
Nor was the feudal system established in any sense by the settlement of the comitatus group on the conquered land.
The bodyguard of the king (comitatus or gesith) is more distinctly dependent upon him.
The viking band, as a development of the Teutonic comitatus, was naturally inspired with its ideas of honour and valour.Canute the Great
Laurence Marcellus Larson