Axle
Middle English (originally axle-tree ): from Old Norse ǫxultré .
wiktionary
From Middle English axel, axle, eaxle, from Old English eaxl(“shoulder, armpit”), from Proto-West Germanic *ahslu(“shoulder”), from Proto-Germanic *ahslō(“shoulder”), from Proto-Indo-European*h₂eḱs-l-eh₂, from *h₂eḱs-(“axis, axle”). Cognate with Saterland Frisian acsle(“shoulder”), Dutch oksel(“armpit”), German Achsel(“armpit”), Swedish axel(“shoulder”), Latin axilla(“armpit”), Latin axis(“axle”), Greek άξονας(áxonas, “axle”), Sanskrit अक्ष(ákṣa, “axle”), Sanskrit कक्ष(kakṣá, “room, armpit”), Russian ось(osʹ, “axle”).
From Middle English axil, in turn a combination of Old English eax and Old Norse ǫxull.
etymonline
axle (n.)
"pole or pin upon which a wheel revolves" (properly, the round ends of the axle-tree which are inserted in the hubs or naves of the wheels), 1630s, from Middle English axel-, from some combination of Old English eax and Old Norse öxull "axis," both from Proto-Germanic *akhsulaz (source also of Old English eaxl "shoulder," oxta, ohsta "armpit," which survived as dialectal oxter; also Old Saxon ahsla, Old High German ahsala, German Achsel "shoulder"), from PIE *aks- "axis" (see axis, which is from the Latin cognate of this Germanic word). Found only in compound axle-tree before 14c.
