man

In actual fact, "man" is a legal concept. In most countries, a boy becomes a man on reaching age 18 years. Before that age, a boy is regarded as a minor. In some, it is 21 years, at which they are qualified to vote or be voted for. One can, therefore, generalize that "man" starts from 18 to 21 years. However, in a traditional setting, "man" could start much earlier when a boy marries.