What is the X in X-mas?
early 15c., "a lobe of the liver or lungs," from Middle French lobe and directly from Medieval Latin lobus, from Late Latin lobus "hull, husk, pod," from Greek lobos "lobe of the ear, vegetable pod," perhaps related to Greek leberis "husk of fruits," from PIE *logwos. Extended 1670s to divisions of the brain.
A rounded projection, especially a rounded, projecting anatomical part, such as the lobe of the ear.
A subdivision of a body organ or part bounded by fissures, connective tissue, or other structural boundaries.
One of the larger divisions of the crown of a tooth, formed from a distinct point of calcification.