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.
Girls usually complete puberty by ages 15â17, while boys usually complete puberty by ages 16â17. The major landmark of puberty for females is menarche, the onset of menstruation, which occurs on average between ages 12â13; for males, it is the first ejaculation, which occurs on average at age 13.uberty in boys starts off more slowly than in girls, but then speeds up later on. Although boys are usually about 2 centimetres (0.8 in) shorter than girls before puberty begins, men on average end up about 13 centimetres (5.1 in) taller than women.