运气 (yùnqi)

运气 refers to luck or fortune, the force that causes things to go well or badly beyond one's control.

Meanings

今天我的运气真好，找到了钱包。 Jīntiān wǒ de yùnqi zhēn hǎo, zhǎodào le qiánbāo. My luck was really good today; I found my wallet.

不要只靠运气，努力才是关键。 Bùyào zhǐ kào yùnqi, nǔlì cái shì guānjiàn. Do not just rely on luck; hard work is the key.

他真倒霉，运气太差了。 Tā zhēn dǎoméi, yùnqi tài chà le. He is really unlucky; his luck is terrible.

祝你好运气！ Zhù nǐ hǎo yùnqi! Wishing you good luck!

运 means "to transport/carry" and 气 means "energy/air" — luck is like a current of energy that either carries you forward or holds you back.