Emily Dickinson Lexicon

TROOP, n. [Fr. troupe; It. truppa; Sp. and Port. tropa; Dan. and D. trop; G. trupp; Sw. tropp. The Gaelic trapan, a bunch or cluster, is probably the same word. The sense is a crowd, or a moving crowd.]

1. A collection of people; a company; a number; a multitude. Gen. xlix. 2 Sam. xxiii. Hos. vii. That which should accompany old age, / As honor, love, obedience, troops of friends, / I must not look to have. Shak.
2. A body of soldiers. But applied to infantry, it is now used in the plural, troops, and this word signifies soldiers in general, whether more or less numerous, including infantry, cavalry and artillery. We apply the word to a company, a regiment or an army. The captain ordered his troops to halt; the colonel commanded his troops to wheel and take a position on the flank; the general ordered his troops to attack; the troops of France amounted to 400,000 men.
3. Troop, in the singular, a small body or company of cavalry, light horse or dragoons, commanded by a captain.
4. A company of stage-players. Coxe's Russ.