上午(shàng wǔ) - morning in Mandarin

上午 (shàngwǔ) covers the morning: 上 (shàng, "above, before") plus 午 (wǔ, "noon"), literally "before noon", the whole stretch from getting up to the approach of midday.

It is broader than 早上 (zǎoshang, "early morning"), which really only covers the first hour or two after waking. 上午 (shàngwǔ) is the block a timetable, a shop, or a doctor's surgery actually uses: 医院上午八点开门 (yīyuàn shàngwǔ bā diǎn kāimén), "the hospital opens at eight in the morning".

上午 (shàngwǔ) pairs naturally against 中午 (zhōngwǔ, "midday") and 下午 (xiàwǔ, "afternoon") to divide the daytime into three: 我们上午开会，下午休息 (wǒmen shàngwǔ kāihuì, xiàwǔ xiūxi), "we have a meeting in the morning and rest in the afternoon".