borrowed from Latin āla "armpit, upper arm, wing, axil" going back to *akslā, going back to Indo-European *h2eḱs-(i)l-eh2- (whence also Germanic *ahslō-, whence Old English eaxl "shoulder," Old Frisian axle, axele "shoulder, armpit," Old Saxon ahsla, Old High German ahsla, ahsala, Old Icelandic ǫxl "shoulder"), derivative with an -l- suffix from *h2eḱs- "pivot around which something rotates, axle" — more at axis