sprag

• 名词，指为防止车轮或车辆滑动而垫在车轮下或轮辐之间的楔形块或木块，也指矿井中支撑顶板的木支柱。

A noun referring to a chock or bar wedged under a wheel or between spokes to prevent a vehicle from rolling, or a wooden prop used to support a mine roof.

1. Wheel chockC1formal

   A chock or bar wedged under a wheel or between the spokes to prevent a vehicle from rolling down an incline.

   车轮挡块

   • The driver placed a sprag under the truck's wheel before unloading.
   • He used a wooden sprag to keep the cart from moving on the hill.
   • Always secure a sprag when parking on a steep slope.

   同义词blockchockscotchstopwedge

2. Mine supportC1formal

   A wooden prop used to support the roof of a mine.

   矿用支柱

   • The miners installed a sprag to reinforce the tunnel ceiling.
   • A broken sprag can cause a dangerous collapse underground.
   • They replaced the old sprag with a new timber support.

   同义词propstaysupport