means The period during which a child's body matures sexually and physically into that of an adult, driven by a surge of hormones.

from From Latin pubertas, meaning 'adult age' or 'manhood,' rooted in puber, 'adult,' literally 'covered with hair' — the same pubes that gives us 'pubic.' The Romans, ever practical, defined growing up by the visible evidence: the arrival of body hair marked the official transition into adulthood. It entered English in the late Middle Ages by way of Latin.