形容词
名词
1. 军团;兵团
A legion is a large group of soldiers who form one section of an army.
2. 众多;大批;大量
A legion of people or things is a great number of them.
3. 比比皆是的;不胜枚举的;多如牛毛的
If you say that things of a particular kind are legion, you mean that there are a great number of them.