Source : Webster's Revised Unabridged Dictionary (1913)

Rare \Rare\, a. [Compar. {Rarer}; superl. {Rarest}.] [Cf. AS.
   hr[=e]r, or E. rare early.]
   Nearly raw; partially cooked; not thoroughly cooked;
   underdone; as, rare beef or mutton.

         New-laid eggs, which Baucis' busy care Turned by a
         gentle fire, and roasted rare.           --Dryden.

   Note: This word is in common use in the United States, but in
         England its synonym underdone is preferred.

Rare \Rare\, a. [Compar. {Rarer}; superl. {Rarest}.] [F., fr. L.
   rarus thin, rare.]
   1. Not frequent; seldom met with or occurring; unusual; as, a
      rare event.

   2. Of an uncommon nature; unusually excellent; valuable to a
      degree seldom found.

            Rare work, all filled with terror and delight.
                                                  --Cowley.

            Above the rest I judge one beauty rare. --Dryden.

   3. Thinly scattered; dispersed.

            Those rare and solitary, three in flocks. --Milton.

   4. Characterized by wide separation of parts; of loose
      texture; not thick or dense; thin; as, a rare atmosphere
      at high elevations.

            Water is nineteen times lighter, and by consequence
            nineteen times rarer, than gold.      --Sir I.
                                                  Newton.

   Syn: Scarce; infrequent; unusual; uncommon; singular;
        extraordinary; incomparable.

   Usage: {Rare}, {Scarce}. We call a thing rare when but few
          examples, specimens, or instances of it are ever to be
          met with; as, a rare plant. We speak of a thing as
          scarce, which, though usually abundant, is for the
          time being to be had only in diminished quantities;
          as, a bad harvest makes corn scarce.

                A perfect union of wit and judgment is one of
                the rarest things in the world.   --Burke.

                When any particular piece of money grew very
                scarce, it was often recoined by a succeeding
                emperor.                          --Addison.