We usually have lunch around meridiem.

我们通常在正午左右吃午饭。

She always takes a short nap at meridiem.

她总是在正午时小睡一会儿。

The sun is at its highest point at meridiem.

太阳在正午时达到最高点。

The clock struck twelve, marking the meridiem.

钟敲响了十二点，标志着正午的到来。

The temperature often peaks at meridiem during summer.

夏天的温度通常在正午时达到最高点。