Dictionary of Family Names

AYRES, AYARS, AYERS, AYRIS, AYRS.   Bardsley has:  A nickname; no doubt a variant of Ayre or Eyre, q.v., with the patronymic s suffixed, as in Jones, Simmons, Roberts, &c.   Therefore, literally "the son of the heir."   Several families of Ayres or Aires went out to America in the 17th century, which fact accounts for its familiar recurrence in the United States; v. index, Hotten's Lists of Emigrants. 

Arthur has:  AYRES.   Derived from a river, town, and district of the same name in Scotland.    Air, Gaelic.  Derivation uncertain.  It may come from Iar, west—the course in which the river runs; or Air, slaughter, the place of battle.  The Celtic Aer, and the Welsh Awyr, signify, radically, to open, expand or flow clearly; to shoot or radiate.  In Thorpe's catalogue of the deeds of Battle Abbey, we find the following legendary account of this name:

"Ayres, formerly Eyre.  The first of this family was named Truelove, one of the followers of William the Conqueror.  At the battle of Hastings, Duke William was flung from his horse, and his helmet beaten into his face, which Truelove observing, pulled off, and horsed him again.  The duke told him 'Thou shalt hereafter from Truelove be called Eyre (or Air), because thou hast given me the air I breathe.'  After the battle, the Duke, on inquiry respecting him, found him severely wounded (his leg and thigh having been struck off); he ordered him the utmost care, and on his recovery, gave him lands in Derby, in reward for his services, and the leg and thigh in armor, cut off, for his crest; an honorary badge yet worn by all the Eyres in England."