中午(zhōng wǔ) - midday in Mandarin

中午 (zhōngwǔ) is midday, noon: 中 (zhōng, "middle") plus 午 (wǔ, "noon"), literally "the middle of noon", the short window around twelve o'clock rather than the whole morning.

It is narrower than 上午 (shàngwǔ, "morning") and 下午 (xiàwǔ, "afternoon") either side of it: those two split the day roughly in half, while 中午 (zhōngwǔ) is really just the hour or so around 十二点 (shí'èr diǎn, "twelve o'clock").

中午 (zhōngwǔ) is also when lunch happens, so it shows up constantly around eating: 我们中午一起吃饭吧 (wǒmen zhōngwǔ yìqǐ chīfàn ba), "let us eat together at midday", with 午饭 (wǔfàn, "lunch") built from the same 午 (wǔ).