The Collaborative International Dictionary of English v.0.48:

Invent \In*vent"\, v. t. [imp. & p. p. Invented; p. pr. & vb.
   n. Inventing.] [L. inventus, p. p. of invenire to come
   upon, to find, invent; pref. in- in + venire to come, akin to
   E. come: cf. F. inventer. See Come.]
   [1913 Webster]
   1. To come or light upon; to meet; to find. [Obs.]
      [1913 Webster]

            And vowed never to return again,
            Till him alive or dead she did invent. --Spenser.
      [1913 Webster]

   2. To discover, as by study or inquiry; to find out; to
      devise; to contrive or produce for the first time; --
      applied commonly to the discovery of some serviceable
      mode, instrument, or machine.
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            Thus first Necessity invented stools. --Cowper.
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   3. To frame by the imagination; to fabricate mentally; to
      forge; -- in a good or a bad sense; as, to invent the
      machinery of a poem; to invent a falsehood.
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            Whate'er his cruel malice could invent. --Milton.
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            He had invented some circumstances, and put the
            worst possible construction on others. --Sir W.
                                                  Scott.

   Syn: To discover; contrive; devise; frame; design; fabricate;
        concoct; elaborate. See Discover.
        [1913 Webster]

WordNet (r) 3.0 (2006):

invent
    v 1: come up with (an idea, plan, explanation, theory, or
         principle) after a mental effort; "excogitate a way to
         measure the speed of light" [syn: invent, contrive,
         devise, excogitate, formulate, forge]
    2: make up something artificial or untrue [syn: fabricate,
       manufacture, cook up, make up, invent]