In English, name Kay means – Variant of the Latin: Gaius; an alternative spelling of Cai. Sir Kay was a knight of King Arthurs Round Table. The name Kay also appeared in Hans Christian Andersens story The Snow Queen.. Other origins for name Kay include – English, Greek, Native American, Irish, French, Welsh, Scottish. Name Kay is a unisex name and can be used for a boy or girl name (male or female).