spic

The story

First attested in this spelling in the 1910s, from earlier spig, spiggoty, spikity, generally taken to derive from a (stereotype of a) Hispanic pronunciation of "(no) speak d(e) English" (especially as used by the laborers who dug the Panama Canal). There are also later (1960s) suggestions that the term referred instead to Italians and derives from spaghetti, but there is little to back this up.