Source : Webster's Revised Unabridged Dictionary (1913)

Fool \Fool\, n. [OE. fol, n. & adj., F. fol, fou, foolish, mad;
   a fool, prob. fr. L. follis a bellows, wind bag, an inflated
   ball; perh. akin to E. bellows. Cf. {Folly}, {Follicle}.]
   1. One destitute of reason, or of the common powers of
      understanding; an idiot; a natural.

   2. A person deficient in intellect; one who acts absurdly, or
      pursues a course contrary to the dictates of wisdom; one
      without judgment; a simpleton; a dolt.

            Extol not riches, then, the toil of fools. --Milton.

            Experience keeps a dear school, but fools will learn
            in no other.                          --Franklin.

   3. (Script.) One who acts contrary to moral and religious
      wisdom; a wicked person.

            The fool hath said in his heart, There is no God.
                                                  --Ps. xiv. 1.

   4. One who counterfeits folly; a professional jester or
      buffoon; a retainer formerly kept to make sport, dressed
      fantastically in motley, with ridiculous accouterments.

            Can they think me . . . their fool or jester?
                                                  --Milton.

   {April fool}, {Court fool}, etc. See under {April}, {Court},
      etc.

   {Fool's cap}, a cap or hood to which bells were usually
      attached, formerly worn by professional jesters.

   {Fool's errand}, an unreasonable, silly, profitless adventure
      or undertaking.

   {Fool's gold}, iron or copper pyrites, resembling gold in
      color.

   {Fool's paradise}, a name applied to a limbo (see under
      {Limbo}) popularly believed to be the region of vanity and
      nonsense. Hence, any foolish pleasure or condition of vain
      self-satistaction.

   {Fool's parsley} (Bot.), an annual umbelliferous plant
      ({[AE]thusa Cynapium}) resembling parsley, but nauseous
      and poisonous.

   {To make a fool of}, to render ridiculous; to outwit; to
      shame. [Colloq.]

   {To play the fool}, to act the buffoon; to act a foolish
      part. ``I have played the fool, and have erred
      exceedingly.'' --1 Sam. xxvi. 21.

Gold \Gold\ (g[=o]ld), n. [AS. gold; akin to D. goud, OS. & G.
   gold, Icel. gull, Sw. & Dan. guld, Goth. gul[thorn], Russ. &
   OSlav. zlato; prob. akin to E. yellow. [root]49, 234. See
   {Yellow}, and cf. {Gild}, v. t.]
   1. (Chem.) A metallic element, constituting the most precious
      metal used as a common commercial medium of exchange. It
      has a characteristic yellow color, is one of the heaviest
      substances known (specific gravity 19.32), is soft, and
      very malleable and ductile. It is quite unalterable by
      heat, moisture, and most corrosive agents, and therefore
      well suited for its use in coin and jewelry. Symbol Au
      (Aurum). Atomic weight 196.7.

   Note: Native gold contains usually eight to ten per cent of
         silver, but often much more. As the amount of silver
         increases, the color becomes whiter and the specific
         gravity lower. Gold is very widely disseminated, as in
         the sands of many rivers, but in very small quantity.
         It usually occurs in quartz veins (gold quartz), in
         slate and metamorphic rocks, or in sand and alluvial
         soil, resulting from the disintegration of such rocks.
         It also occurs associated with other metallic
         substances, as in auriferous pyrites, and is combined
         with tellurium in the minerals petzite, calaverite,
         sylvanite, etc. Pure gold is too soft for ordinary use,
         and is hardened by alloying with silver and copper, the
         latter giving a characteristic reddish tinge. [See
         {Carat}.] Gold also finds use in gold foil, in the
         pigment purple of Cassius, and in the chloride, which
         is used as a toning agent in photography.

   2. Money; riches; wealth.

            For me, the gold of France did not seduce. --Shak.

   3. A yellow color, like that of the metal; as, a flower
      tipped with gold.

   4. Figuratively, something precious or pure; as, hearts of
      gold. --Shak.

   {Age of gold}. See {Golden age}, under {Golden}.

   {Dutch gold}, {Fool's gold}, {Gold dust}, etc. See under
      {Dutch}, {Dust}, etc.

   {Gold amalgam}, a mineral, found in Columbia and California,
      composed of gold and mercury.

   {Gold beater}, one whose occupation is to beat gold into gold
      leaf.

   {Gold beater's skin}, the prepared outside membrane of the
      large intestine of the ox, used for separating the leaves
      of metal during the process of gold-beating.

   {Gold beetle} (Zo["o]l.), any small gold-colored beetle of
      the family {Chrysomelid[ae]}; -- called also {golden
      beetle}.

   {Gold blocking}, printing with gold leaf, as upon a book
      cover, by means of an engraved block. --Knight.

   {Gold cloth}. See {Cloth of gold}, under {Cloth}.

   {Gold Coast}, a part of the coast of Guinea, in West Africa.
      

   {Gold cradle}. (Mining) See {Cradle}, n., 7.

   {Gold diggings}, the places, or region, where gold is found
      by digging in sand and gravel from which it is separated
      by washing.

   {Gold end}, a fragment of broken gold or jewelry.

   {Gold-end man}.
      (a) A buyer of old gold or jewelry.
      (b) A goldsmith's apprentice.
      (c) An itinerant jeweler. ``I know him not: he looks like
          a gold-end man.'' --B. Jonson.

   {Gold fever}, a popular mania for gold hunting.

   {Gold field}, a region in which are deposits of gold.

   {Gold finder}.
      (a) One who finds gold.
      (b) One who empties privies. [Obs. & Low] --Swift.

   {Gold flower}, a composite plant with dry and persistent
      yellow radiating involucral scales, the {Helichrysum
      St[oe]chas} of Southern Europe. There are many South
      African species of the same genus.

   {Gold foil}, thin sheets of gold, as used by dentists and
      others. See {Gold leaf}.

   {Gold} {knobs or knoppes} (Bot.), buttercups.

   {Gold lace}, a kind of lace, made of gold thread.

   {Gold latten}, a thin plate of gold or gilded metal.

   {Gold leaf}, gold beaten into a film of extreme thinness, and
      used for gilding, etc. It is much thinner than gold foil.
      

   {Gold lode} (Mining), a gold vein.

   {Gold mine}, a place where gold is obtained by mining
      operations, as distinguished from diggings, where it is
      extracted by washing. Cf. {Gold diggings} (above).

   {Gold nugget}, a lump of gold as found in gold mining or
      digging; -- called also a {pepito}.

   {Gold paint}. See {Gold shell}.

   {Gold or Golden}, {pheasant}. (Zo["o]l.) See under
      {Pheasant}.

   {Gold plate}, a general name for vessels, dishes, cups,
      spoons, etc., made of gold.

Source : WordNet®

fool's gold
     n : a common mineral (iron disulfide) that has a pale yellow
         color [syn: {pyrite}, {iron pyrite}]