四维的英文：
extremities

Four-dimensional space-time defies visualization
四维空时难以形象表示。

The adjuster that moves the seat up and down and from front to rear is called a four-way adjuster.
能够把座位升高、降低和向前后倾斜的调节器叫做"四维调节器"。

in an extremity
智尽力竭|陷入绝境

relative extreme
相对极值

It is extremely corrosive.
它是极强的腐蚀剂。

It was an extremely fine day .
那是一个非常晴朗的日子。

An extremity of a solid is a surface.
立体的边界之一是一个面。