concave

凹面或凹曲线。

A concave surface or curve.

苍穹；天空的穹隆。

The vault of the sky.

托勒密或地心说世界模型中的天体球之一。

One of the celestial spheres of the Ptolemaic or geocentric model of the world.

采矿和收割中用于将有用物料与尾矿或谷壳分离的弧形格栅部件。

An element of a curved grid used to separate desirable material from tailings or chaff in mining and harvesting.

冲浪板底部的一道凹槽,用于增加升力。

An indentation running along the base of a surfboard, intended to increase lift.

滑板顶部凹陷的区域,用于放置脚部并增加板身强度。

An indented area on the top of a skateboard, providing a position for foot placement and increasing board strength.

为作弊而制成凹形的扑克牌。

A playing card made concave for use in cheating.