Transferred use of the surname, in origin a local name from the English county. This is probably named with a Celtic word meaning ‘border’. Use as a given name is of recent origin, but it is now quite popular. It may in part be seen as a short form of Kenton.
Scottish and northern Irish: of uncertain origin; probably a variant spelling of Smillie, but perhaps a habitational name, a variant of Smalley, or a nickname from Middle English smile ‘smile’, ‘grin’.