inside; within; inner; internal; specifically refers to the interior or domestic domain as opposed to the exterior or foreign domain; often used in spatial or temporal contexts

a hexagon; hexagonal; sexangular; having six angles or corners

cylinder; column; also called 圆柱体 yuán​zhù​tǐ

the top, end, or tip of an object; the beginning or end of an event

A metal fastener consisting of a cylindrical or conical rod with a spiral thread; also called 螺丝钉 luó​sī​dīng or 螺丝 luó​sī.