This is the 862nd most frequent Russian word.
максим
The Russian word "максим" is a male given name, equivalent to "Maxim" in English.
Here, "Максим" is used as a proper noun, being the name of a person.
Максим каждый день гуляет с собакой.
Maxim walks his dog every day.
In this sentence, "максим" refers to the word root meaning "maximum" or "utmost," used as a part of a derived form.
Максим усилий был достигнут перед экзаменом.
The maximum effort was exerted before the exam.
Here, the term "максим" is part of the adjective "максимального," meaning "maximum" or "greatest," related to achieving the utmost level.