noun · A general term for an object or matter, often used informally or disparagingly.

这是个什么玩意儿？

noun · A trick or performance in a stage show, circus, or acrobatics.

变戏法这类玩意儿他很拿手。

noun · An object for a child to play with; a plaything.

这种小玩意儿孩子们很喜欢。