legion

American  

[lee-juhn] / ˈli dʒən /

noun

1. a division of the Roman army, usually comprising 3000 to 6000 soldiers.

2. a military or semimilitary unit.

3. the Legion.

   1. American Legion.

   2. foreign legion.

4. any large group of armed men.

5. any great number of persons or things; multitude.

   Synonyms:

   sea, host, mass, throng

---

adjective

1. very great in number.

   The holy man's faithful followers were legion.

legion British  

/ ˈliːdʒən /

noun

1. a military unit of the ancient Roman army made up of infantry with supporting cavalry, numbering some three to six thousand men

2. any large military force

   the French Foreign Legion

3. (usually capital) an association of ex-servicemen

   the British Legion

4. (often plural) any very large number, esp of people

---

adjective

1. (usually postpositive) very large or numerous

Usage

What is a legion? A legion is a large group of people or things, most commonly soldiers, as in World-famous author Stephen King has a legion of fans. Legion can also describe a very large number, as in The number of soccer fans around the world is legion. During the Roman Empire, legion referred to a division of the army that numbered between 3,000 to 6,000 soldiers. As a result, we use legion to refer to a large number of soldiers. However, legion is now used more generally to mean any big group of people or things. Example: The city was filled with legions of fans after the rock star announced they would perform a concert there.

Etymology

Origin of legion

1175–1225; Middle English legi ( o ) un (< Old French ) < Latin legiōn- (stem of legiō ) picked body of soldiers, equivalent to leg ( ere ) to gather, choose, read + -iōn- -ion

Example Sentences

A legion of fans cheered on watching a computerized visualization of the race.

From The Wall Street Journal • Apr. 7, 2026

He's one of a legion of often young people seen zipping around some of Britain's cities on bright green hired e-scooters and e-bikes operated by US company Lime.

From BBC • Apr. 3, 2026

A legion of historians, Angelenos and Monroe fans claimed the 1920s haunt, where the actor died in 1962, is an indelible piece of the city’s history.

From Los Angeles Times • Feb. 3, 2026

With its trademark improvisational, genre-blending style, the band became known for never performing the same show twice, winning an avid and diverse legion of fans, and selling millions of records.

From Barron's • Jan. 11, 2026

He wondered who was defending Camp Jupiter now that the legion had marched east, especially with all the monsters Gaea was unleashing from the Doors of Death.

From "The House of Hades" by Rick Riordan

Related Words

• army
• flock
• horde
• multitude
• throng