Man
A man is a male human. The term man is usually reserved for an adult male, with the term boy being the usual term for a male child or adolescent. However, the term man is also sometimes used to identify a male human, regardless of age, as in phrases such as "men's basketball".
Like most other male mammals, a man's genome typically inherits an X chromosome from his mother and a Y chromosome from his father. The male fetus produces larger amounts of androgens and smaller amounts of estrogens than a female fetus. This difference in the relative amounts of these sex steroids is largely responsible for the physiological differences that distinguish men from women. During puberty, hormones which stimulate androgen production result in the development of secondary sexual characteristics, thus exhibiting greater differences between the sexes. However, there are exceptions to the above for some intersex and transgender men.
Etymology
The English term "man" is derived from a Proto-Indo-European root *man- (see Sanskrit/Avestan manu-, Slavic mǫž "man, male"). More directly, the word derives from Old English mann. The Old English form had a default meaning of "adult male" (which was the exclusive meaning of wer), though it could also signify a person of unspecified gender. The closely related Old English pronoun man was used just as it is in Modern German to designate "one" (e. g., in the saying man muss mit den Wölfen heulen).
The Old English form is derived from Proto-Germanic *mannz, "human being, person", which is also the etymon of German Mann "man, husband" and man "one" (pronoun), Old Norse maðr, and Gothic manna. According to Tacitus, the mythological progenitor of the Germanic tribes was called Mannus. *Manus in Indo-European mythology was the first man, see Mannus, Manu (Hinduism).
