Dictionary.com
Thesaurus.com
Synonyms

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adjective

  1. (usually postpositive) very large or numerous

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Fischbach is hardly a newcomer to the industry – he's built a platform over 14 years and has a captive audience in his legions of fans.

From BBC

Black mascara stained Leerdam’s cheeks as she skated around the arena, saluting the legion of Dutch fans that filled the stands.

From Los Angeles Times

Brad Karp, who helped legions of clients navigate boardroom intrigue, was pushed out from the chairmanship of Paul Weiss by an internal revolt after his chummy emails with Jeffrey Epstein came to light.

From The Wall Street Journal

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

But Shiffrin’s willingness to show her vulnerable side—often in real time, right there at the finish, with a TV camera in her face—has cultivated a new legion of fans, especially outside of skiing.

From The Wall Street Journal