Troop

1. n. A particular roll of the drum; a quick march.
2. n. A collection of people; a company; a number; a multitude.
3. n. Soldiers, collectively; an army; — now generally used in the plural.
4. n. Specifically, a small body of cavalry, light horse, or dragoons, consisting usually of about sixty men, commanded by a captain; the unit of formation of cavalry, corresponding to the company in infantry. Formerly, also, a company of horse artillery; a battery.
5. n. A company of stageplayers; a troupe.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.