The Mandarin word for "thing" or "things" is dōngxi. It is made up of two characters: 東 (dōng) means "east" and 西 (xī) means "west".

When these two characters are used together, 東西 can mean "east and west", but more commonly they refer to things in general.
Examples

    Wǒ yào qù mǎi dōngxi.
    我要去買東西｡
    我要去买东西｡
    I am going shopping. (I am going to buy things.)

    Nèi gè dà de dōngxi shì shénme?
    那個大的東西是什麼?
    那个大的东西是什么?
    What is that big thing? (or "those big things")