Updated June 9, 2019 Find Baby Names Boy name origins & meanings Latin : Rejoice; variation of Gaius Boy name variations Caius Caius + 9% this year Masculine Rare READ MORE DETAILS Cai Cai + 18% this year Masculine Rare READ MORE DETAILS Caio Caio - 6% this year Masculine Rare READ MORE DETAILS Kay Kay + 10% this year Neutral Rare READ MORE DETAILS Kaye Kaye + 15% this year Masculine Rare READ MORE DETAILS Keye Keye 0 % this year Masculine Rare READ MORE DETAILS Keys Keys 0 % this year Masculine Rare READ MORE DETAILS Cais Cais 0 % this year Masculine Rare READ MORE DETAILS Family name origins & meanings English : variant of Kay.English (of Norman origin) : habitational name from Guise in Aisne, Picardy, which is first recorded in the 12th century as Gusia; the etymology is uncertain.Irish : Anglicized form of Gaelic Mac Aodha (see McKay).