Drawing a straight line on a piece of stone and make the surface curved naturally on one side, the curved surface sprawl across the other three edges.

在一块石板上刻画一条直线，在线的一侧做成起伏不定的自然曲面，曲面向另外三边自由蔓延。

youdao

The curved upper surface of a nonturbulent liquid in a container that is concave if the liquid wets the container walls.

弯月面容器中之静止液体的弯曲上表面，如果液体浸润了容器壁，那么弯曲面呈凹状。

youdao

Once they hit the edge of a cone, drops are propelled towards its base, the least curved region, because of the pressure difference caused by surface tension.

一旦水滴流到了圆锥体的边缘，就会在锥体表面张力所形成的压力差的作用下流向它的底座，那里是曲线弧度最小的地方。

youdao

"Well,one of the things that's interesting about these flexible sheets is that they can be curved, so you could imagine putting them in unconventional forms, like on the surface of a vehicle or something like that, where you don't have a flat surface."

VOA: standard.2010.02.19

In particular, the processes by which the circuit pattern is first projected on to a chip's surface lithographically, and then etched on to it chemically, will need to be altered to take account of the fact that the surface is curved.

ECONOMIST: Semiconductors

There was no visible wood grain in the print, and its shape indicated it was taken from a curved surface, not a flat one.

BBC: Fingerprint evidence is fallible

The projection provided a solution to a puzzle that had troubled mapmakers since the world was recognized as a sphere: How does one represent the curved surface of the globe on a flat chart?

WSJ: Lost in Our Maps: A History of Cartographic Catastrophes