thelarche /thilär″kē/ [Gk, thele, nipple, archaios, beginning] , the beginning of female pubertal breast development, normally occurring between 9 and 13 years of age. Thelarche occurs before puberty at the beginning of the phase of rapid growth. Premature thelarche is precocious breast development in a female without other evidence of sexual maturation. Compare menarche.
