abnormally early sexual maturity, usually before the age of 8 years in a girl and 9 years in a boy. True precocious puberty is marked by mature gonads capable of ovulation or spermatogenesis, adult levels of female or male sex hormones, and secondary sexual characteristics. Pseudoprecocious puberty is a condition usually caused by an endocrine tumor that results only in premature development of secondary sex characteristics. Also called pubertas praecox.