lobe (n.) Look up lobe at Dictionary.com
early 15c., "a lobe of the liver or lungs," from Medieval Latin lobus "a lobe," from Late Latin lobus "hull, husk, pod," from Greek lobos "lobe, lap, slip; vegetable pod," used of lap- or slip-like parts of the body or plants, especially "earlobe," but also of lobes of the liver or lungs, a word of unknown origin. It is perhaps related to Greek leberis "husk of fruits," from PIE *logwos. Beekes writes that the proposed connection with the PIE source of English lap (n.1)) "is semantically attractive." Extended 1670s to divisions of the brain; 1889 to ice sheets. The common notion is "rounded protruding part."