Why is Waterford called the Déise?

AMG National Association Trust Bank 14 Basile State Bank 4 Brazos National Bank 2 CBW Bank 14 CITIZENS Bank 2 FIRST CAROLINA Bank 14 First Citizens State Bank 7 First State Bank of Bedias 7 Geo. D. Warthen Bank 13 HABIB AMER Bank 19 Highlands Community Bank 3 OCEANFIRST Bank National Association 11 OPTUS Bank 19 OSB Community Bank 10 PARAGON Bank 18 Putnam County National Bank of Carmel 15 Spur Security Bank 4 UNION Bank 21 VILLAGE B&TC National Association 3 Western National Bank, Cass Lake 2