The Collaborative International Dictionary of English v.0.48:

Congress \Con"gress\, n.; pl. Congresses. [L. congressus, fr.
   congredi, p. p. -gressus, to go or come together; con- +
   grati to go or step, gradus step: cf. F. congr?s. See
   Grade.]
   1. A meeting of individuals, whether friendly or hostile; an
      encounter. [Obs.]
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            Here Pallas urges on, and Lausus there;
            Their congress in the field great Jove withstands.
                                                  --Dryden.
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   2. A sudden encounter; a collision; a shock; -- said of
      things. [Obs.]
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            From these laws may be deduced the rules of the
            congresses and reflections of two bodies. --Cheyne.
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   3. The coming together of a male and female in sexual
      commerce; the act of coition. --Pennant.
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   4. A gathering or assembly; a conference.
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   5. A formal assembly, as of princes, deputies,
      representatives, envoys, or commissioners; esp., a meeting
      of the representatives of several governments or societies
      to consider and determine matters of common interest.
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            The European powers strove to . . . accommodate
            their differences at the congress of Vienna.
                                                  --Alison.
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   6. The collective body of senators and representatives of the
      people of a nation, esp. of a republic, constituting the
      chief legislative body of the nation.
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   Note: In the Congress of the United States (which took the
         place of the Federal Congress, March 4, 1789), the
         Senate consists of two Senators from each State, chosen
         by the State legislature for a term of six years, in
         such a way that the terms of one third of the whole
         number expire every year; the House of Representatives
         consists of members elected by the people of the
         several Congressional districts, for a term of two
         years, the term of all ending at the same time. The
         united body of Senators and Representatives for any
         term of two years for which the whole body of
         Representatives is chosen is called one Congress. Thus
         the session which began in December, 1887, was the
         first (or long) session, and that which began in
         December, 1888, was the second (or short) session, of
         the Fiftieth Congress. When an extra session is had
         before the date of the first regular meeting of a
         Congress, that is called the first session, and the
         following regular session is called the second session.
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   7. The lower house of the Spanish Cortes, the members of
      which are elected for three years.
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   The Continental Congress, an assembly of deputies from the
      thirteen British colonies in America, appointed to
      deliberate in respect to their common interests. They
      first met in 1774, and from time thereafter until near the
      close of the Revolution.

   The Federal Congress, the assembly of representatives of
      the original States of the American Union, who met under
      the Articles of Confederation from 1781 till 1789.

   Congress boot or Congress gaiter, a high shoe or
      half-boot, coming above the ankle, and having the sides
      made in part of some elastic material which stretches to
      allow the boot to be drawn on and off. [U.S.]

   Congress water, a saline mineral water from the Congress
      spring at Saratoga, in the State of New York.

   Syn: Assembly; meeting; convention; convocation; council;
        diet; conclave; parliament; legislature.
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