1830, Christ-kinkle (in a Pennsylvania German context, and as a reminiscence of times past, so probably at least a generation older in that setting), from German Christkindlein, Christkind'l "Christ child." Second element is a diminutive of German Kind "child" (see kin (n.)). Properly Baby Jesus, not Santa Claus.
kreutzer
kriegspiel
krill
kris
Krishna
Kriss Kringle
Kristallnacht
krone
kroner
Krugerrand
krummhorn