Source : Webster's Revised Unabridged Dictionary (1913)

Troop \Troop\, n.
   See {Boy scout}, above.

Troop \Troop\, v. t.

   {To troop the} {colors or colours} (Mil.), in the British
      army, to perform a ceremony consisting essentially in
      carrying the colors, accompained by the band and escort,
      slowly before the troops drawn up in single file and
      usually in a hollow square, as in London on the
      sovereign's birthday. Trooper \Troop"er\, n.
   A mounted policeman. [Australia]

   Note: The {black troopers} of Queensland are a regiment of
         aboriginal police, employed chiefly for dispersing wild
         aborigines who encroach on sheep runs.

Troop \Troop\, v. i. [imp. & p. p. {Trooped}; p. pr. & vb. n.
   {Trooping}.]
   1. To move in numbers; to come or gather in crowds or troops.
      ``Armies . . . troop to their standard.'' --Milton.

   2. To march on; to go forward in haste.

            Nor do I, as an enemy to peace, Troop in the throngs
            of military men.                      --Shak.

Troop \Troop\, n. [F. troupe, OF. trope, trupe, LL. troppus; of
   uncertain origin; cf. Icel. [thorn]orp a hamlet, village, G.
   dorf a village, dial. G. dorf a meeting. Norw. torp a little
   farm, a crowd, E. thorp. Cf. {Troupe}.]
   1. A collection of people; a company; a number; a multitude.

            That which should accompany old age -- As honor,
            love, obedience, troops of friends -- I must not
            look to have.                         --Shak.

   2. Soldiers, collectively; an army; -- now generally used in
      the plural.

            Farewell the plumed troop, and the big wars. --Shak.

            His troops moved to victory with the precision of
            machines.                             --Macaulay.

   3. (Mil.) 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.

   4. A company of stageplayers; a troupe. --W. Coxe.

   5. (Mil.) A particular roll of the drum; a quick march.

Source : WordNet®

troop
     v 1: march in a procession; "the veterans paraded down the
          street" [syn: {parade}, {promenade}]
     2: move or march as if in a crowd; "They children trooped into
        the room"

troop
     n 1: a group of soldiers
     2: a cavalry unit corresponding to an infantry company
     3: a unit of girl or boy scouts [syn: {scout troop}, {scout
        group}]
     4: an orderly crowd; "a troop of children" [syn: {flock}]