The Collaborative International Dictionary of English v.0.48:

Impeachment \Im*peach"ment\, n. [Cf. F. emp[^e]chement.]
   The act of impeaching, or the state of being impeached; as:
   (a) Hindrance; impediment; obstruction. [Obs.]
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             Willing to march on to Calais,
             Without impeachment.                 --Shak.
   (b) A calling to account; arraignment; especially, of a
       public officer for maladministration.
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             The consequence of Coriolanus' impeachment had like
             to have been fatal to their state.   --Swift.
   (c) A calling in question as to purity of motives, rectitude
       of conduct, credibility, etc.; accusation; reproach; as,
       an impeachment of motives. --Shak.
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   Note: In England, it is the privilege or right of the House
         of Commons to impeach, and the right of the House of
         Lords to try and determine impeachments. In the United
         States, it is the right of the House of Representatives
         to impeach, and of the Senate to try and determine
         impeachments.
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   Articles of impeachment. See under Article.

   Impeachment of waste (Law), restraint from, or
      accountability for, injury; also, a suit for damages for
      injury. --Abbott.
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The Collaborative International Dictionary of English v.0.48:

Article \Ar"ti*cle\, n. [F., fr. L. articulus, dim. of artus
   joint, akin to Gr. ?, fr. a root ar to join, fit. See Art,
   n.]
   1. A distinct portion of an instrument, discourse, literary
      work, or any other writing, consisting of two or more
      particulars, or treating of various topics; as, an article
      in the Constitution. Hence: A clause in a contract, system
      of regulations, treaty, or the like; a term, condition, or
      stipulation in a contract; a concise statement; as,
      articles of agreement.
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   2. A literary composition, forming an independent portion of
      a magazine, newspaper, or cyclopedia.
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   3. Subject; matter; concern; distinct. [Obs.]
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            A very great revolution that happened in this
            article of good breeding.             --Addison.
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            This last article will hardly be believed. --De Foe.
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   4. A distinct part. "Upon each article of human duty."
      --Paley. "Each article of time." --Habington.
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            The articles which compose the blood. --E. Darwin.
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   5. A particular one of various things; as, an article of
      merchandise; salt is a necessary article.
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            They would fight not for articles of faith, but for
            articles of food.                     --Landor.
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   6. Precise point of time; moment. [Obs. or Archaic]
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            This fatal news coming to Hick's Hall upon the
            article of my Lord Russell's trial, was said to have
            had no little influence on the jury and all the
            bench to his prejudice.               --Evelyn.
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   7. (Gram.) One of the three words, a, an, the, used before
      nouns to limit or define their application. A (or an) is
      called the indefinite article, the the definite article.
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   8. (Zool.) One of the segments of an articulated appendage.
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   Articles of Confederation, the compact which was first made
      by the original thirteen States of the United States. They
      were adopted March 1, 1781, and remained the supreme law
      until March, 1789.

   Articles of impeachment, an instrument which, in cases of
      impeachment, performs the same office which an indictment
      does in a common criminal case.

   Articles of war, rules and regulations, fixed by law, for
      the better government of the army.

   In the article of death [L. in articulo mortis], at the
      moment of death; in the dying struggle.

   Lords of the articles (Scot. Hist.), a standing committee
      of the Scottish Parliament to whom was intrusted the
      drafting and preparation of the acts, or bills for laws.


   The Thirty-nine Articles, statements (thirty-nine in
      number) of the tenets held by the Church of England.
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Bouvier's Law Dictionary, Revised 6th Ed (1856):

ARTICLES OF IMPEACHMENT. An instrument which, in cases of impeachment, (q.v.)
is used, and performs the same office which an indictment does, in a
common criminal case, is known by this name. These articles do not usually
pursue the strict form and accuracy of an indictment., Wood. Lect. 40, p.
605; Foster, 389, 390; Com. Dig. Parliament, L 21. They are sometimes quite
general in the form of the allegations, but always contain, or ought to
contain, so much certainty, as to enable the party to put himself on the
proper defence, and in case of an acquittal, to avail himself of it, as a
bar to another impeachment. Additional articles may, perhaps, be exhibited
at any stage of the prosecution. Story on the Sec. 806; Rawle on the Const.
216.
     2. The answer to articles of impeachment is exempted from observing
great strictness of form; and it may contain arguments as well as facts. It
is usual to give a full and particular answer to each article of the
accusation. Story, Sec. 808.