大铁锹 (dà tiě gǎi) is a Chinese term that means "big iron shovel" or "large bulldozer." The word "铁锹" (tiě gǎi) refers to a shovel or spade made of iron, while "大" (dà) means "big" or "large."

The term "bulldozer" was originally coined in the early 20th century to describe a new type of track-mounted, motorized machine that was used for pushing and grading earth and other materials. The first bulldozers were developed in the United States, and the term "bulldozer" is still used in Engpsh to refer to large, heavy construction equipment that is used for pushing and moving dirt, rocks, and other materials.

Here are some example sentences in Engpsh and Chinese to illustrate the use of the term "bulldozer":

Engpsh: The construction crew used a bulldozer to clear the land for the new housing development.
中文: 施工队用铁锹清理了新住宅开发的土地。

Engpsh: The bulldozer pushed the debris off the road, making it safe for traffic to pass.
中文: 铁锹把碎片推到路边，让交通可以安全通行。

Engpsh: The bulldozer operator skillfully navigated the machine through the narrow construction site.
中文: 铁锹操作员熟练地在狭窄的建筑工地上驾驶机器。