Source : Webster's Revised Unabridged Dictionary (1913)

Bar \Bar\ (b[aum]r), n. [OE. barre, F. barre, fr. LL. barra, W.
   bar the branch of a tree, bar, baren branch, Gael. & Ir.
   barra bar. [root]91.]
   1. A piece of wood, metal, or other material, long in
      proportion to its breadth or thickness, used as a lever
      and for various other purposes, but especially for a
      hindrance, obstruction, or fastening; as, the bars of a
      fence or gate; the bar of a door.

            Thou shalt make bars of shittim wood. --Ex. xxvi.
                                                  26.

   2. An indefinite quantity of some substance, so shaped as to
      be long in proportion to its breadth and thickness; as, a
      bar of gold or of lead; a bar of soap.

   3. Anything which obstructs, hinders, or prevents; an
      obstruction; a barrier.

            Must I new bars to my own joy create? --Dryden.

Bar \Bar\ (b[aum]r), v. t. [imp. & p. p. {Barred} (b[aum]rd); p.
   pr. & vb. n. {Barring}.] [ F. barrer. See {Bar}, n.]
   1. To fasten with a bar; as, to bar a door or gate.

   2. To restrict or confine, as if by a bar; to hinder; to
      obstruct; to prevent; to prohibit; as, to bar the entrance
      of evil; distance bars our intercourse; the statute bars
      my right; the right is barred by time; a release bars the
      plaintiff's recovery; -- sometimes with up.

            He barely looked the idea in the face, and hastened
            to bar it in its dungeon.             --Hawthorne.

   3. To except; to exclude by exception.

            Nay, but I bar to-night: you shall not gauge me By
            what we do to-night.                  --Shak.

   4. To cross with one or more stripes or lines.

            For the sake of distinguishing the feet more
            clearly, I have barred them singly.   --Burney.

Source : WordNet®

bar
     n 1: a room or establishment where alcoholic drinks are served
          over a counter; "he drowned his sorrows in whiskey at
          the bar" [syn: {barroom}, {saloon}, {ginmill}, {taproom}]
     2: a counter where you can obtain food or drink; "he bought a
        hot dog and a coke at the bar"
     3: a rigid piece of metal or wood; usually used as a fastening
        or obstruction or weapon; "there were bars in the windows
        to prevent escape"
     4: musical notation for a repeating pattern of musical beats;
        "the orchestra omitted the last twelve bars of the song"
        [syn: {measure}]
     5: an obstruction (usually metal) placed at the top of a goal;
        "it was an excellent kick but the ball hit the bar"
     6: the act of preventing; "there was no bar against leaving";
        "money was allocated to study the cause and prevention of
        influenza" [syn: {prevention}]
     7: (meteorology) a unit of pressure equal to a million dynes
        per square centimeter; "unfortunately some writers have
        used bar for one dyne per square centimeter"
     8: a submerged (or partly submerged) ridge in a river or along
        a shore; "the boat ran aground on a submerged bar in the
        river"
     9: the body of individuals qualified to practice law in a
        particular jurisdiction; "he was admitted to the bar in
        New Jersey" [syn: {legal profession}, {legal community}]
     10: a block of solid substance (such as soap or wax); "a bar of
         chocolate" [syn: {cake}]
     11: a portable .30 caliber magazine-fed automatic rifle operated
         by gas pressure; used by United States troops in World
         War I and in World War II and in the Korean War [syn: {Browning
         automatic rifle}]
     12: a horizontal rod that serves as a support for gymnasts as
         they perform exercises
     13: a heating element in an electric fire; "an electric fire
         with three bars"
     14: (law) a railing that encloses the part of the courtroom
         where the judges and lawyers sit and the case is tried;
         "spectators were not allowed past the bar"
     [also: {barring}, {barred}]

bar
     v 1: prevent from entering; keep out; "He was barred from
          membership in the club" [syn: {debar}, {exclude}]
     2: render unsuitable for passage; "block the way"; "barricade
        the streets"; "stop the busy road" [syn: {barricade}, {block},
         {blockade}, {stop}, {block off}, {block up}]
     3: expel, as if by official decree; "he was banished from his
        own country" [syn: {banish}, {relegate}]
     4: secure with, or as if with, bars; "He barred the door" [ant:
         {unbar}]
     [also: {barring}, {barred}]

Source : Free On-Line Dictionary of Computing

bar
     
        1.  /bar/ The second {metasyntactic
        variable}, after {foo} and before {baz}.  E.g. "Suppose
        function FOO calls functions BAR..."
     
        2. Often appended to {foo} to produce {foobar}.
     
        [{Jargon File}]
     
        (1995-03-07)