Kumbaya. Also spelled kum ba yah, cumbayah, kumbayah, and probably a few other ways. If you look in a good songbook you'll find the word helpfully translated as "come by here";
Kumbaya apparently originated with the Gullah, an African-American people living on the Sea Islands and adjacent coastal regions of South Carolina and Georgia. (The best known Sea Island is Hilton Head, the resort area.) Having lived in isolation for hundreds of years, the Gullah speak a dialect that most native speakers of English find unintelligible on first hearing but that turns out to be heavily accented English with other stuff mixed in. The dialect appears in Joel Chandler Harris's "Uncle Remus" stories, to give you an idea what it sounds like. In the 1940s the pioneering linguist Lorenzo Turner showed that the Gullah language was actually a creole consisting of English plus a lot of words and constructions from the languages of west Africa, the Gullahs' homeland. Although long scorned as an ignorant caricature of English, Gullah is actually a language of considerable charm, with expressions like (forgive my poor attempt at expressing these phonetically) deh clin, dawn (literally "day clean"); troot mout, truthful person ("truth mouth"), and tebble tappuh, preacher ("table tapper").