Source : Webster's Revised Unabridged Dictionary (1913)

Ingenious \In*gen"ious\, a. [L. ingeniosus, fr. ingenium innate
   or natural quality, natural capacity, genius: cf. F.
   ing['e]nieux. See {Engine}.]
   1. Possessed of genius, or the faculty of invention; skillful
      or promp to invent; having an aptitude to contrive, or to
      form new combinations; as, an ingenious author, mechanic.

            A man . . . very wise and ingenious in feats of war.
                                                  --Hakluyt.

            Thou, king, send out For torturers ingenious.
                                                  --Shak.

            The more ingenious men are, the more apt are they to
            trouble themselves.                   --Sir W.
                                                  Temple.

   2. Proseeding from, pertaining to, or characterized by,
      genius or ingenuity; of curious design, structure, or
      mechanism; as, an ingenious model, or machine; an
      ingenious scheme, contrivance, etc.

            Thus men go wrong with an ingenious skill. --Cowper.

   3. Witty; shrewd; adroit; keen; sagacious; as, an ingenious
      reply.

   4. Mental; intellectual. [Obs.]

            A course of learning and ingenious studies. --Shak.

Source : WordNet®

ingenious
     adj 1: (used of persons or artifacts) marked by independence and
            creativity in thought or action; "an imaginative use
            of material"; "the invention of the knitting frame by
            another ingenious English clergyman"- Lewis Mumford;
            "an ingenious device"; "had an inventive turn of
            mind"; "inventive ceramics" [syn: {imaginative}, {inventive}]
     2: skillful (or showing skill) in adapting means to ends; "cool
        prudence and sensitive selfishness along with quick
        perception of what is possible--these distinguish an
        adroit politician"; "came up with a clever story"; "an
        ingenious press agent"; "an ingenious scheme" [syn: {adroit},
         {clever}]
     3: showing inventiveness and skill; "a clever gadget"; "the
        cunning maneuvers leading to his success"; "an ingenious
        solution to the problem" [syn: {clever}, {cunning}]