Plural form of 'man' (男) with the pluralizing suffix '‑tachi', referring to a group of men or males.
男たちは夜遅くまで居酒屋で語り合っていた。
The men were talking together at the izakaya late into the night.
海に出た男たちは翌朝まで戻らなかった。
The men who went out to sea didn't return until the next morning.
その映画は若い男たちの友情を描いている。
That movie depicts the friendship of young men.