In US urban slang, particularly in African American and Latino slang, the term boy is used with a possessive as meaning friend (my boy, his boys), presumably as a reduction of homeboy, originally a male from the same area.In some cases, the word boy is used merely to designate the age of the (male) person, irrespective of the function, as in altar boy, a minor acting as liturgical acolyte, or in Boy Scouts, an organisation specifically for boys.
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").
In some Middle Eastern cultures, characteristics affirming boyhood include physiological features associated with prepubescence, such as pubelessness and the inability to ejaculate.
An adult male human is a man, but when age is not a crucial factor, both terms can be interchangeable, e.g., 'boys and their toys' applies equally to adults and young boys, just as 'Are you mice or men? The age boundary is not clear cut, rather dependent on the context or even on individual circumstances.
It is most common to refer to men, irrespective of age or even in an adult age group, as boys in the context of a team (especially all-male), such as old boys for networking of adult men who attended the same school(s) as boys, or as professional colleagues, e.g.
"the boys at the office, - police station etc." (often all adults).Many occasions occur when an adult male is commonly referred to as a boy.A person's boyfriend or loverboy may be of any age; this even applies to a 'working' call-boy, toyboy (though usually younger than the client as youth is generally considered attractive).Expressions such as "boys will be boys" (i.e., a male always retains a tendency for boyish games or mischief) allude to stereotypically ascribed characteristics of boys and men; in the term tomboy, a woman's (according to the counterpart-gender stereotype) uncharacteristically bold nature is even described solely by comparing her to a boy.The use of boy (like kid) in (fantasy or descriptive) nicknames, also for adult men (e.g.Furthermore, the word may be related to Bōia, an Anglo-Saxon personal name.