百无聊赖

bǎi wú liáo lài

bored stiff

Character by character

百bǎi
hundred

无wú
without

聊liáo
rely

赖lài
depend

下雨天出不了门，他百无聊赖地刷着手机。

Stuck indoors on a rainy day, he scrolled his phone out of sheer boredom.

Tone: neutral.

More literary than 无聊; 聊赖 means something to lean on.

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