late puberty

In girls, delayed sexual development is defined as lack of any breast development by 14 years of age or when more than five years pass between initial growth of breast tissue and menarche.... In boys, delayed sexual development is defined as no testicular enlargement by 14 years of age or the passing of five years between the initial and complete development of the genitalia.
http://www.aafp.org/afp/990700ap/209.html