The Collaborative International Dictionary of English v.0.48:

Conceit \Con*ceit"\, n. [Through French, fr. L. conceptus a
   conceiving, conception, fr. concipere to conceive: cf. OF. p.
   p. nom. conciez conceived. See Conceive, and cf. Concept,
   Deceit.]
   1. That which is conceived, imagined, or formed in the mind;
      idea; thought; image; conception.
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            In laughing, there ever procedeth a conceit of
            somewhat ridiculous.                  --Bacon.
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            A man wise in his own conceit.        --Prov. xxvi.
                                                  12.
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   2. Faculty of conceiving ideas; mental faculty; apprehension;
      as, a man of quick conceit. [Obs.]
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            How often, alas! did her eyes say unto me that they
            loved! and yet I, not looking for such a matter, had
            not my conceit open to understand them. --Sir P.
                                                  Sidney.
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   3. Quickness of apprehension; active imagination; lively
      fancy.
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            His wit's as thick as Tewksbury mustard; there's
            more conceit in him than is in a mallet. --Shak.
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   4. A fanciful, odd, or extravagant notion; a quant fancy; an
      unnatural or affected conception; a witty thought or turn
      of expression; a fanciful device; a whim; a quip.
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            On his way to the gibbet, a freak took him in the
            head to go off with a conceit.        --L'Estrange.
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            Some to conceit alone their works confine,
            And glittering thoughts struck out at every line.
                                                  --Pope.
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            Tasso is full of conceits . . . which are not only
            below the dignity of heroic verse but contrary to
            its nature.                           --Dryden.
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   5. An overweening idea of one's self; vanity.
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            Plumed with conceit he calls aloud.   --Cotton.
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   6. Design; pattern. [Obs.] --Shak.
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   In conceit with, in accord with; agreeing or conforming.

   Out of conceit with, not having a favorable opinion of; not
      pleased with; as, a man is out of conceit with his dress.


   To put [one] out of conceit with, to make one indifferent
      to a thing, or in a degree displeased with it.
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The Collaborative International Dictionary of English v.0.48:

Conceit \Con*ceit"\, v. t.
   To conceive; to imagine. [Archaic]
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         The strong, by conceiting themselves weak, are therebly
         rendered as inactive . . . as if they really were so.
                                                  --South.
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         One of two bad ways you must conceit me,
         Either a coward or a flatterer.          --Shak.
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The Collaborative International Dictionary of English v.0.48:

Conceit \Con*ceit"\, v. i.
   To form an idea; to think. [Obs.]
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         Those whose . . . vulgar apprehensions conceit but low
         of matrimonial purposes.                 --Milton.
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WordNet (r) 3.0 (2006):

conceit
    n 1: feelings of excessive pride [syn: amour propre,
         conceit, self-love, vanity]
    2: an elaborate poetic image or a far-fetched comparison of very
       dissimilar things
    3: a witty or ingenious turn of phrase; "he could always come up
       with some inspired off-the-wall conceit"
    4: an artistic device or effect; "the architect's brilliant
       conceit was to build the house around the tree"
    5: the trait of being unduly vain and conceited; false pride
       [syn: conceit, conceitedness, vanity] [ant:
       humbleness, humility]