Barnum \b(a)-rnum, bar-num\ as a boy's name is of Old English origin. Possibly derived from "Baron's home". In America, inseparable from Phineas T. Barnum, founder of Barnum & Bailey's circus and one of America's great showmen.
Barnum has 1 variant form: Barnham.
A baby name that sounds like Barnum is Brynmor.