earlobe (n.)

"organ of hearing," Old English eare "ear," from Proto-Germanic *auzon (source also of Old Norse eyra, Danish øre, Old Frisian are, Old Saxon ore, Middle Dutch ore, Dutch oor, Old High German ora, German Ohr, Gothic auso), from PIE *ous- "ear" (source also of Greek ous, Latin auris, Lithuanian ausis, Old Church Slavonic ucho, Old Irish au "ear," Avestan usi "the two ears").

þe harde harte of man, þat lat in godis word atte ton ere & vt atte toþir. [sermon, c. 1250]

In music, "capability to learn and reproduce by hearing," 1520s, hence play by ear (1670s). The belief that itching or burning ears means someone is talking about you is mentioned in Pliny's "Natural History" (77 C.E.). Until at least the 1880s, even some medical men still believed piercing the ear lobes improved one's eyesight. The meaning "handle of a pitcher" is mid-15c. (but compare Old English earde "having a handle," and the image also was in ancient Greek).

To be wet behind the ears "naive" is from 1902, American English. The warning phrase walls have ears is attested from 1610s. French orielle, Spanish oreja are from Latin auricula (Medieval Latin oricula), diminutive of auris.

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."