army

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A large body of people organized and trained for land warfare.
2. n. The entire military land forces of a country.
3. n. A tactical and administrative military unit consisting of a headquarters, two or more corps, and auxiliary forces.
4. n. A large group of people organized for a specific cause: the construction army that built the Panama Canal.
5. n. A multitude; a host: An army of waiters served at the banquet. See Synonyms at multitude.

Century Dictionary and Cyclopedia

1. Consisting of or abounding in arms or branches; branching; spreading.
2. n. An armed expedition.
3. n. A large body of men trained and armed for war, and organized in companies, battalions, regiments, brigades, or similar divisions, under proper officers. In general, an army in modern times consists of infantry and cavalry, with artillery, although the union of the three is not essential to its constitution, the two latter being adjuncts to the infantry. Armies are designated, according to their objects, duties, field of operations, etc., as offensive or defensive, covering, blockading, besieging, standing or regular, army of obstruction, army of observation, army of invasion, army of occupation, army of reserve, etc. The forces employed in the large war-fleets of former times were called naval armies.
4. n. A great number; a vast multitude.

Wiktionary

1. n. A large, highly organized military force, concerned mainly with ground (rather than air or naval) operations.
2. n. The governmental agency in charge of a state's army.
3. n. figuratively A large group of people working toward the same purpose.
4. n. figuratively A large group of social animals working toward the same purpose.
5. n. figuratively Any multitude.

GNU Webster's 1913

1. n. A collection or body of men armed for war, esp. one organized in companies, battalions, regiments, brigades, and divisions, under proper officers.
2. n. A body of persons organized for the advancement of a cause.
3. n. A great number; a vast multitude; a host.

WordNet 3.0

1. n. a large number of people united for some specific purpose
2. n. the army of the United States of America; the agency that organizes and trains soldiers for land warfare
3. n. a permanent organization of the military land forces of a nation or state