What is the term for the growth of body hair on a male during puberty?

The growth of body hair in males during puberty is classified as a secondary sex characteristic. This term refers to features that develop during puberty that are not directly involved in reproduction but serve to distinguish the sexes. Secondary sex characteristics typically include changes such as increased muscle mass, body hair growth, and voice deepening, which develop as a result of hormonal changes, primarily testosterone.

Understanding this distinction is important because primary sex characteristics refer to the sexual organs and structures directly involved in reproduction, while secondary sex characteristics encompass traits that emerge during puberty and are not directly related to reproductive capability. The terms tertiary sex characteristics and genital characteristics are less commonly used in this context. Tertiary characteristics do not have a widely accepted definition in relation to puberty and sex differentiation, thus reinforcing the appropriateness of referring to body hair growth as a secondary sex characteristic.