不bù耻chǐ下xià问wèn

Literal: not ashamed to ask those below
Figurative: To not be ashamed to ask questions of or seek advice from those beneath you in knowledge, age or rank; to be humble enough to learn from anyone.

Where does 不耻下问 come from?

Kong Yu, a high official (dafu) of the state of Wei, was given the posthumous honorific title "Wen" (the Cultured) after his death. The disciple Zigong, who did not think it fully deserved, asked Confucius why Kong Wenzi merited such a lofty name. Confucius replied that he was quick-minded and fond of learning, and that he "was not ashamed to ask those of lower rank and lesser learning" (不耻下问), which is why he was called "the Cultured." With this phrase Confucius praised the humility of someone who pursues knowledge without caring about appearing inferior. From there it came to praise anyone willing to learn from anybody.

Source (出处): 《论语·公冶长》

How is 不耻下问 used? Two examples

他tā虽suī然rán是shì经jīng理lǐ，但dàn遇yù到dào不bù懂dǒng的de事shì还hái是shì会huì不bù耻chǐ下xià问wèn，向xiàng新xīn来lái的de同tóng事shì请qǐng教jiào。
Although he is the manager, when he runs into something he doesn't understand he isn't ashamed to ask and seeks advice from the new colleague.
想xiǎng把bǎ中zhōng文wén学xué好hǎo，就jiù要yào不bù耻chǐ下xià问wèn，多duō问wèn老lǎo师shī和hé同tóng学xué。
If you want to learn Chinese well, you shouldn't be ashamed to ask and should question teachers and classmates often.

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