army (n.)

late 14c., armee, "armed expedition," from Old French armée "armed troop, armed expedition" (14c.), from Medieval Latin armata "armed force," from Latin armata, fem. of armatus "armed, equipped, in arms," as a noun, "armed men, soldiers," past participle of armare "to arm," literally "act of arming," related to arma "tools, arms" (see arm (n.2)).

Originally used of expeditions on sea or land; the restriction to "land force" is by late 18c. The transferred meaning "host, multitude" is by c. 1500. The meaning "body of men trained and equipped for war" is from 1550s.

The Old English words were here (still preserved in derivatives such as harrier; see harry (v.)), from Proto-Germanic *harjan, from PIE *korio- "people, crowd;" and fierd, with an original sense of "expedition," from Proto-Germanic *farthi-, related to faran "travel" (see fare (v.)). In spite of etymology, in the Anglo-Saxon Chronicle here generally meant "invading Vikings" and fierd was used for the local militias raised to fight them. Army-ant is from 1863, so called for marching in immense numbers.

updated on September 25, 2022

Definitions of army from WordNet
army (n.)
a permanent organization of the military land forces of a nation or state;
Synonyms: regular army / ground forces
army (n.)
a large number of people united for some specific purpose;
Army (n.)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare;
Synonyms: United States Army / US Army / U. S. Army / usa
Etymologies are not definitions. From, not affiliated with etymonline.