The Collaborative International Dictionary of English v.0.48:

Red \Red\, a. [Compar. Redder (-d?r); superl. Reddest.] [OE.
   red, reed, AS. re['a]d, re['o]d; akin to OS. r[=o]d, OFries.
   r[=a]d, D. rood, G. roht, rot, OHG. r[=o]t, Dan. & Sw.
   r["o]d, Icel. rau[eth]r, rj[=o][eth]r, Goth. r['a]uds, W.
   rhudd, Armor. ruz, Ir. & Gael. ruadh, L. ruber, rufus, Gr.
   'eryqro`s, Skr. rudhira, rohita; cf. L. rutilus. [root]113.
   Cf. Erysipelas, Rouge, Rubric, Ruby, Ruddy,
   Russet, Rust.]
   Of the color of blood, or of a tint resembling that color; of
   the hue of that part of the rainbow, or of the solar
   spectrum, which is furthest from the violet part. "Fresh
   flowers, white and reede." --Chaucer.
   [1913 Webster]

         Your color, I warrant you, is as red as any rose.
                                                  --Shak.
   [1913 Webster]

   Note: Red is a general term, including many different shades
         or hues, as scarlet, crimson, vermilion, orange red,
         and the like.
         [1913 Webster]

   Note: Red is often used in the formation of self-explaining
         compounds; as, red-breasted, red-cheeked, red-faced,
         red-haired, red-headed, red-skinned, red-tailed,
         red-topped, red-whiskered, red-coasted.
         [1913 Webster]

   Red admiral (Zool.), a beautiful butterfly (Vanessa
      Atalanta) common in both Europe and America. The front
      wings are crossed by a broad orange red band. The larva
      feeds on nettles. Called also Atalanta butterfly, and
      nettle butterfly.

   Red ant. (Zool.)
   (a) A very small ant (Myrmica molesta) which often infests
       houses.
   (b) A larger reddish ant (Formica sanguinea), native of
       Europe and America. It is one of the slave-making
       species.

   Red antimony (Min.), kermesite. See Kermes mineral
   (b), under Kermes.

   Red ash (Bot.), an American tree (Fraxinus pubescens),
      smaller than the white ash, and less valuable for timber.
      --Cray.

   Red bass. (Zool.) See Redfish
   (d) .

   Red bay (Bot.), a tree (Persea Caroliniensis) having the
      heartwood red, found in swamps in the Southern United
      States.

   Red beard (Zool.), a bright red sponge (Microciona
      prolifera), common on oyster shells and stones. [Local,
      U.S.]

   Red birch (Bot.), a species of birch (Betula nigra)
      having reddish brown bark, and compact, light-colored
      wood. --Gray.

   Red blindness. (Med.) See Daltonism.

   Red book, a book containing the names of all the persons in
      the service of the state. [Eng.]

   Red book of the Exchequer, an ancient record in which are
      registered the names of all that held lands per baroniam
      in the time of Henry II. --Brande & C.

   Red brass, an alloy containing eight parts of copper and
      three of zinc.

   Red bug. (Zool.)
   (a) A very small mite which in Florida attacks man, and
       produces great irritation by its bites.
   (b) A red hemipterous insect of the genus Pyrrhocoris,
       especially the European species (Pyrrhocoris apterus),
       which is bright scarlet and lives in clusters on tree
       trunks.
   (c) See Cotton stainder, under Cotton.

   Red cedar. (Bot.) An evergreen North American tree
      (Juniperus Virginiana) having a fragrant red-colored
      heartwood.
   (b) A tree of India and Australia (Cedrela Toona) having
       fragrant reddish wood; -- called also toon tree in
       India.

   Red horse. (Zool.)
   (a) Any large American red fresh-water sucker, especially
       Moxostoma macrolepidotum and allied species.
   (b) See the Note under Drumfish.

   Red lead.
   (Chem) See under Lead, and Minium.

   Red-lead ore. (Min.) Same as Crocoite.

   Red liquor (Dyeing), a solution consisting essentially of
      aluminium acetate, used as a mordant in the fixation of
      dyestuffs on vegetable fiber; -- so called because used
      originally for red dyestuffs. Called also red mordant.


   Red maggot (Zool.), the larva of the wheat midge.

   Red manganese. (Min.) Same as Rhodochrosite.

   Red man, one of the American Indians; -- so called from his
      color.

   Red maple (Bot.), a species of maple (Acer rubrum). See
      Maple.

   Red mite. (Zool.) See Red spider, below.

   Red mulberry (Bot.), an American mulberry of a dark purple
      color (Morus rubra).

   Red mullet (Zool.), the surmullet. See Mullet.

   Red ocher (Min.), a soft earthy variety of hematite, of a
      reddish color.

   Red perch (Zool.), the rosefish.

   Red phosphorus. (Chem.) See under Phosphorus.

   Red pine (Bot.), an American species of pine (Pinus
      resinosa); -- so named from its reddish bark.

   Red precipitate. See under Precipitate.

   Red Republican (European Politics), originally, one who
      maintained extreme republican doctrines in France, --
      because a red liberty cap was the badge of the party; an
      extreme radical in social reform. [Cant]

   Red ribbon, the ribbon of the Order of the Bath in England.


   Red sanders. (Bot.) See Sanders.

   Red sandstone. (Geol.) See under Sandstone.

   Red scale (Zool.), a scale insect (Aspidiotus aurantii)
      very injurious to the orange tree in California and
      Australia.

   Red silver (Min.), an ore of silver, of a ruby-red or
      reddish black color. It includes proustite, or light red
      silver, and pyrargyrite, or dark red silver.

   Red snapper (Zool.), a large fish (Lutjanus aya syn.
      Lutjanus Blackfordii) abundant in the Gulf of Mexico and
      about the Florida reefs.

   Red snow, snow colored by a mocroscopic unicellular alga
      (Protococcus nivalis) which produces large patches of
      scarlet on the snows of arctic or mountainous regions.

   Red softening (Med.) a form of cerebral softening in which
      the affected parts are red, -- a condition due either to
      infarction or inflammation.

   Red spider (Zool.), a very small web-spinning mite
      (Tetranychus telarius) which infests, and often
      destroys, plants of various kinds, especially those
      cultivated in houses and conservatories. It feeds mostly
      on the under side of the leaves, and causes them to turn
      yellow and die. The adult insects are usually pale red.
      Called also red mite.

   Red squirrel (Zool.), the chickaree.

   Red tape,
   (a) the tape used in public offices for tying up documents,
       etc. Hence,
   (b) official formality and delay; excessive bureaucratic
       paperwork.

   Red underwing (Zool.), any species of noctuid moths
      belonging to Catacola and allied genera. The numerous
      species are mostly large and handsomely colored. The under
      wings are commonly banded with bright red or orange.

   Red water, a disease in cattle, so called from an
      appearance like blood in the urine.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Betula nigra
    n 1: birch of swamps and river bottoms throughout the eastern
         United States having reddish-brown bark [syn: black
         birch, river birch, red birch, Betula nigra]