Among the ancient Romans, a body of soldiers divided into coborts, maniples, and centuries, and consisting of from 3000 to 6000 men; a military force; a great number. Legion of honour, an order instituted in France, by Napoleon, as a reward for merit, both civil and military.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)
A division of the ancient Roman army; an army; a great number.
- The Winston Simplified Dictionary. By William Dodge Lewis, Edgar Arthur Singer. Published 1919. (noun) (n.) (noun)
Among the Romans, a body of soldiers of about 5000 men; a great number; legion of honour, a French order of merit instituted by Napoleon I. when First Consul of France; legion, as in the Scripture phrase, their name is legion, signifies " very many in number".
- Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874. (noun) (n.) (noun)
In ancient Rome, a body of soldiers of from three to six thousand; a military force: a great number.
- The american dictionary of the english language. By Daniel Lyons. Published 1899. (noun) (n.) (noun)
In ancient Rome, a body of soldiers of from 3000 to 9000, an armed force; great number.
- The Clarendon dictionary. By William Hand Browne, Samuel Stehman Haldeman. Published 1894. (noun) (n.) (noun)

Usage examples:

While the discussion was proceeding, a Roman legion arrived; and the Gauls were driven out of the city, having lost not only their self- possession, but possession of the gold that had been assigned to them.
- The Comic History of Rome by Gilbert Abbott Becket
In 1780 he was commissioned lieutenant- colonel and put in command of the celebrated " Lee's Legion so often referred to and which was a terror to the enemy during the war.
- Sages and Heroes of the American Revolution by L. Carroll Judson
Towards the close of 1802, everything was in the hands of the consul for life, who had a class devoted to him in the clergy; a military order in the legion of honour; an administrative body in the council of state; a machinery for decrees in the legislative assembly; a machinery for the constitution in the senate.
- History of the French Revolution from 1789 to 1814 by F. A. M. Miguet