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.
Puberty occurs during adolescence, which begins as early as age 10 and is usually completed by age 17. For girls, a rising level of oestrogen (female hormone) sets the process in motion. Pelvis and breast development are followed by a spurt in height and then the growth of underarm and pubic hair.