"collarbone," 1610s, from Middle French clavicule "collarbone" (16c.), also "small key," from Medieval Latin clavicula "collarbone" (used c.980 in a translation of Avicenna), special use of classical Latin clavicula, literally "small key, bolt," diminutive of clavis "key" (see slot (n.2)); in the anatomical sense a loan-translation of Greek kleis "key, collarbone." So called supposedly from its function as the "fastener" of the shoulder. Related: Clavicular.
clavicle clav·i·cle (klāv'ĭ-kəl)
n.
Either of two slender bones that extend from the manubrium of the sternum to the acromion of the scapula. Also called collarbone.
curved anterior bone of the shoulder (pectoral) girdle in vertebrates; it functions as a strut to support the shoulder