The word kike was born on Ellis Island when there were Jewish migrants who were also illiterate (or could not use Latin alphabet letters). When asked to sign the entry-forms with the customary "X", the Jewish immigrants would refuse, because they associated an X with the cross of Christianity.
@Pain66
Instead, they drew a circle as the signature on the entry-forms. The Yiddish word for "circle" is kikel (pronounced KY - kel), and for "little circle", kikeleh. Before long the immigration inspectors were calling anyone who signed with an "O" instead of an "X" a kikel or kikeleh or kikee or, finally and succinctly, kike.[5]
https://en.wikipedia.org/wiki/Kike