Updated June 9, 2019 Share: Boy name origins & meanings Greek : Beaver Boy name variations Castor Castor 0 % this year Masculine Rare Find out more Castorio Castorio 0 % this year Masculine Rare Find out more Kastor Kastor 0 % this year Masculine Rare Find out more Kaster Kaster 0 % this year Masculine Rare Find out more How Popular Is The Name Caster Family name origins & meanings English : variant spelling of Castor.Americanized spelling of German Kaster.