jujube n.

late 14c., "date-like fruit from a tree found in Asia," from Old French jujube or Medieval Latin jujuba (plural), ill-formed medieval representatives of Late Latin zizyphum, from zizyphus, name of an Asiatic tree with datelike fruit, from Greek zizyphon, from Persian zayzafun. For consonant shift, compare jealous from zealous. The meaning "soft candy with date-like flavor" first recorded 1835.