This is the 1221st most frequent Japanese word.
せよ
"せよ" is the imperative (command) form of "する," meaning "do" or "must do."
The word "せよ" here functions as a command form of the verb "する," signifying an imperative mood to instruct someone to perform an action.
目的地に着いたら、連絡せよ。
Upon reaching the destination, make contact.
Here, "せよ" provides an instructive tone, urging someone to endure hardships resolutely.
困難に直面したときは忍耐せよ。
When faced with difficulties, exercise patience.
In this example, "避けよ" (a conjugation including "せよ") instructs someone to refrain from a specific action, maintaining its imperative function.