Meaning:

    “壁” means “walls,” and “咚” is an onomatopoeia that mimics the sound of smacking the wall. This term, originating in Japanese (kabe-don), can be roughly translated as “wall-smack.” Ranking among Japan’s top anime buzzwords of 2014, the term refers to a certain position where a man places his hand against a wall, keeping his female partner there so he can lean in for a smooch.

    Example:

    A: 现在年轻人最流行的表白方式是什么？

    Xiànzài niánqīngrén zuì líuxíng de biǎobái fāngshì shì shénme?

    What’s the most popular move among young people to confess with the one they love?

    B: 当然是壁咚。把心爱的人逼到墙角，接下来就是深情一吻。

    Dāngrán shì bìdōng。Bǎ xīn’ài de rén bī dào qiángjiǎo, jiēxiàlái jìushì shēnqíng yīwěn。

    Wall-smack of course. You corner the person you love to the wall, ready to lean in for a smooch.

    A: 怎么好像在演连续剧？

    Zěnme hǎoxiàng zài yǎn liánxùjù?

    Wouldn’t that be a scene from a TV series?

    B: 的确是从日本连续剧开始流行的。

    Díquè shì cóng rìběn liánxùjù kāishǐ líuxíng de。

    Indeed, the idea was first popularized by Japanese TV shows.