men

An irregular plural formed by changing the vowel instead of adding -s. Old English already had menn, and the Germanic relatives change their vowels the same way: German Männer, Danish mænd, Swedish män. Many countable senses of man carry over to the plural, so men can be employees, representatives or servants as well as adult males. The form also covers people in general, a usage taken up under the collective "humanity" meaning. Source

Military usage often contrasts two groups, and men names the usually larger one: the enlisted ranks, set against the commissioned officers above them. That is why a lieutenant tells a sergeant to muster the men in the barracks, and why the usual pairing is "officers and men." The sense is most at home in the plural, used collectively, though the singular survives in phrases such as an enlisted man. Source

The inclusive plural takes in everyone, women and children too. When the Declaration of Independence of 1776 says "all men are created equal," it uses men in this broad sense, though whom it covered in practice is still debated. It survives in older texts and in fantasy fiction, where humans are "men" as one race among elves and dwarves. Source