A boy is a young male human. The term is commonly used for a child or an adolescent. When a male human reaches adulthood, he is usually described as a man.
According to the Merriam-Webster Dictionary, a boy is "a male child from birth to adulthood".
The word "boy" comes from Middle English boi, boye ("boy, servant"), related to other Germanic words for boy, namely East Frisian boi ("boy, young man") and West Frisian boai ("boy"). Although the exact etymology is obscure, the English and Frisian forms probably derive from an earlier Anglo-Frisian *bō-ja ("little brother"), a diminutive of the Germanic root *bō- ("brother, male relation"), from Proto-Indo-European *bhā-, *bhāt- ("father, brother"). The root is also found in Norwegian dialectal boa ("brother"), and, through a reduplicated variant *bō-bō-, in Old Norse bófi, Dutch boef "(criminal) knave, rogue", German Bube ("knave, rogue, boy"). Furthermore, the word may be related to Bōia, an Anglo-Saxon personal name.
Historically, in the United States and South Africa, "boy" was not only a "neutral" term for domestics but also a disparaging term towards black men; the term implied a subservient status. Thomas Branch, an early African-American Seventh-day Adventist missionary to Nyassaland (Malawi) referred to the native students as "boys":Multiple politicians – including New Jersey Governor Chris Christie and former Kentucky Congressman Geoff Davis – have been criticized publicly for referring to a black man as "boy".
During an event promoting the 2017 boxing bout between Floyd Mayweather Jr. and Conor McGregor, the latter told the former to "dance for me, boy." The remarks led several boxers – including Mayweather and Andre Ward – as well as multiple commentators to accuse McGregor of racism.
Human sex is determined at fertilization when the genetic sex of the zygote has been initialized by a sperm cell containing either an X or Y chromosome. If this sperm cell contains an X chromosome, it will coincide with the X chromosome of the ovum and a girl will develop.