Type Word Usage Old Welsh Meaning & History Old Welsh word meaning "great, big" [1]. Related ItemsDetails Other Languages & Culturesmāros(Old Celtic) mór(Old Irish) Given Name DescendantsPellinore(Arthurian Cycle) Trevor(English) Brynmor, Gwynfor, Trefor, Trevor(Welsh) Surname DescendantTrevor(Welsh) Place Name DescendantTrefor(Welsh) Sources & References Matasović, Ranko. Etymological Dictionary of Proto-Celtic. Brill, 2009, page 258.