noun, Psychiatry. 1. an inability to speak, due to a physical defect, conscious refusal, or psychogenic inhibition. Origin of mutism.
1 A new study finds girls are developing breasts earlier than ever before; American boys and girls are entering puberty about five years younger than they did in 1920.
Quick Answer. On average, girls reach their final adult height and stop growing by age 14 or 15, though this figure skews either younger or older depending on when puberty begins. Most girls experience a growth spurt between ages 10 to14, and a female's rate of growth peaks around two years after puberty begins, which is usually around age 12. Keep Learning.