suru verb (special), transitive verb
Formal or literary verb for making a promise or commitment. In everyday speech, 約束する is much more common.
彼は必ず戻ると約した。
He promised that he would definitely return.
suru verb (special), transitive verb
Used for condensing or shortening a text, explanation, or process. Often appears in formal or academic contexts.
長い報告書を約して要点だけを伝えた。
I abridged the long report and conveyed only the main points.
suru verb (special), transitive verb
Mathematical term for reducing a fraction, equation, or expression to a simpler form.
分数を約して簡単な形にする。
Reduce the fraction to a simpler form.