Source : Webster's Revised Unabridged Dictionary (1913)

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.

            In laughing, there ever procedeth a conceit of
            somewhat ridiculous.                  --Bacon.

            A man wise in his own conceit.        --Prov. xxvi.
                                                  12.

   2. Faculty of conceiving ideas; mental faculty; apprehension;
      as, a man of quick conceit. [Obs.]

            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.

   3. Quickness of apprehension; active imagination; lively
      fancy.

            His wit's as thick as Tewksbury mustard; there's
            more conceit in him than is in a mallet. --Shak.

   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.

            On his way to the gibbet, a freak took him in the
            head to go off with a conceit.        --L'Estrange.

            Some to conceit alone their works confine, And
            glittering thoughts struck out at every line.
                                                  --Pope.

            Tasso is full of conceits . . . which are not only
            below the dignity of heroic verse but contrary to
            its nature.                           --Dryden.

   5. An overweening idea of one's self; vanity.

            Plumed with conceit he calls aloud.   --Cotton.

   6. Design; pattern. [Obs.] --Shak.

   {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.

Conceit \Con*ceit"\, v. i.
   To form an idea; to think. [Obs.]

         Those whose . . . vulgar apprehensions conceit but low
         of matrimonial purposes.                 --Milton.

Conceit \Con*ceit"\, v. t.
   To conceive; to imagine. [Archaic]

         The strong, by conceiting themselves weak, are therebly
         rendered as inactive . . . as if they really were so.
                                                  --South.

         One of two bad ways you must conceit me, Either a
         coward or a flatterer.                   --Shak.

Source : WordNet®

conceit
     n 1: feelings of excessive pride [syn: {amour propre}, {self-love},
           {vanity}]
     2: the trait of being vain and conceited [syn: {vanity}]