Shapewear is any of various undergarments designed to give the wearer a slimmer appearance. The function of a shapewear is not to enhance¹ a bodily feature, but to smooth or control the display of one.

Shapewear（塑身内衣）是指那些可以让你看起来变瘦的内衣。塑身内衣并不能真正地改变你的体型，只是能在视觉上调整你的体型，让你看起来更瘦，更有曲线。

For example:

The shapewear sucks all that stuff in. It's so funny that when you take them off you just become a blob. You look in the mirror, and it's like, hey, now I'm an amoeba. (Source: New York Times)

塑身内衣似乎把身上的赘肉都吸进去了。不过一旦你脱下它，你的身体还是有一团团的赘肉。你在镜子里看着自己，会觉得自己好像变形成另外一个人一样。