Meridiem is a Latin term that refers to the middle of the day, typically noon. There are numerous synonyms for this word, including midday, noon, noontide, and mid-morning. These words are commonly used in the English language, especially in formal contexts, to describe the time of day when the sun is at its highest point. Other words that can be used as synonyms for meridiem include mid-afternoon, noonday, and high noon. Regardless of the word chosen, all of these synonyms refer to the same period in time and are interchangeable in most situations.