正規分布等のグラフの「裾」は"tails"と言うようです。
One can see that the normal density allocates little probability mass to the regions far from the mean ("has thin tails")(Wiki, Kurtosis, 尖度)
Log-log plots are an alternative way of graphically examining the tail of a distribution using a random sample.(Wiki, Power law、冪乗則）
It is assumed here that a random sample is obtained from a probability distribution, and that we want to know if the tail of the distribution follows a power law (in other words, we want to know if the distribution has a "Pareto tail")（Ｗｉｋｉ、パレート分布）
tail index: 裾指数
