Type Word Usage Old Irish Meaning & History Old Irish word meaning "might, power" [1]. Related ItemsFamily Tree·Details Other Languages & Culturesbrigā(Old Celtic) Given Name DescendantsBreana, Breann, Breanna, Breanne, Bree, Brian, Briana, Brianna, Brianne, Brion, Bryan, Bryana, Bryanna, Bryant, Bryon, Bryanne(English) Brian(Irish) Brígh(Irish Mythology) Brian(Old Irish) Brajan(Polish) Brayan(Spanish) Surname DescendantsBryan, Bryant(English) Ó Briain, O'Brian, O'Brien(Irish) Sources & References Matasović, Ranko. Etymological Dictionary of Proto-Celtic. Brill, 2009, page 77.