Gigantism or giantism, (from Greek gigas, gigantas "giant") is a conition characterized by excessive growth and height significantly above average. As a medical term, gigantism refers to the rare condition of pituitary gigantism due to prepubertal growth hormone excess. There is no precise definition of the degree of height that qualifies a person to be termed a "giant." The term has been typically applied to those whose height is not just in the upper 1% of the population but several standard deviations above mean for persons of the same sex, age, and ethnic ancestry. Typical adult heights of Americans of European descent to whom the term might be applied are 2.10 - 2.40 metres (7 - 8 feet). The term is seldom applied to those whose heights appear to be the healthy result of normal genetics and nutrition.