What is "abrincatui"

The Abrincatui were a Gallic tribe ( Plin. iv. 18), not mentioned by Julius Caesar, whose frontier was near the Curiosolites. Their town Ingena, called Abrincatae in the Notitia dignitatum, has given its name to the modern Avranches; and their territory would probably correspond to the division of Avranchin. The Abrincatui became a client tribe of the Venelli until the Roman occupation in BC 49, when they were separated.