axletree

詳細解釋：

ax.le.tree

n.（名詞）
A crossbar or rod supporting a vehicle, such as a cart, that has terminal spindles on which the wheels revolve.
車軸，軸乾：支撐如二輪馬車等交通工具的橫樑或棍棒，輪子圍繞其上的軸心末端轉動

來源：
Blend of Middle English axel [axle] * see axle
混合了 中古英文 axel [軸] *參見 axle
Middle English axtre [axletree] ax from Old English eax tre [tree] * see tree
中古英文 axtre [軸平] ax 源自 古英文 eax tre [樹] *參見 tree