Definitions
1.NounA soldier belonging to a legion; a professional soldier of the ancient Roman army.
2.NounA person who is neither a citizen nor colonial/imperial subject of the state whose military they join.
3.NounA member of a legion, such as the American Legion, or of any organization containing the term legion in its title (e.g. the French Foreign Legion).
4.AdjectiveRelating to, or consisting of, a legion or legions."a legionary force"
5.AdjectiveContaining a great number.