Source : Webster's Revised Unabridged Dictionary (1913)

Ranger \Ran"ger\, n.
   1. One who ranges; a rover; sometimes, one who ranges for
      plunder; a roving robber.

   2. That which separates or arranges; specifically, a sieve.
      [Obs.] ``The tamis ranger.'' --Holland.

   3. A dog that beats the ground in search of game.

   4. One of a body of mounted troops, formerly armed with short
      muskets, who range over the country, and often fight on
      foot.

   5. The keeper of a public park or forest; formerly, a sworn
      officer of a forest, appointed by the king's letters
      patent, whose business was to walk through the forest,
      recover beasts that had strayed beyond its limits, watch
      the deer, present trespasses to the next court held for
      the forest, etc. [Eng.]

Source : WordNet®

Ranger
     n 1: a member of the Texas state highway patrol; formerly a
          mounted lawman who maintained order on the frontier
          [syn: {Texas Ranger}]
     2: an official who is responsible for managing and protecting
        an area of forest [syn: {fire warden}, {forest fire
        fighter}]
     3: a member of a military unit trained as shock troops for
        hit-and-run raids [syn: {commando}]