The Collaborative International Dictionary of English v.0.48:

Stag \Stag\ (st[a^]g), n. [Icel. steggr the male of several
   animals; or a doubtful AS. stagga. Cf. Steg.]
   1. (Zool.)
      (a) The adult male of the red deer (Cervus elaphus), a
          large European species closely related to the American
          elk, or wapiti.
      (b) The male of certain other species of large deer.
          [1913 Webster]

   2. A colt, or filly; also, a romping girl. [Prov. Eng.]
      [1913 Webster]

   3. A castrated bull; -- called also bull stag, and bull
      seg. See the Note under Ox.
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   4. (Stock Exchange)
      (a) An outside irregular dealer in stocks, who is not a
          member of the exchange. [Cant]
      (b) One who applies for the allotment of shares in new
          projects, with a view to sell immediately at a
          premium, and not to hold the stock. [Cant]
          [1913 Webster]

   5. (Zool.) The European wren. [Prov. Eng.]
      [1913 Webster]

   Stag beetle (Zool.), any one of numerous species of
      lamellicorn beetles belonging to Lucanus and allied
      genera, especially Lucanus cervus of Europe and Lucanus
      dama of the United States. The mandibles are large and
      branched, or forked, whence the name. The larva feeds on
      the rotten wood of dead trees. Called also horned bug,
      and horse beetle.

   Stag dance, a dance by men only. [Slang, U.S.]

   Stag hog (Zool.), the babiroussa.

   Stag-horn coral (Zool.), any one of several species of
      large branching corals of the genus Madrepora, which
      somewhat resemble the antlers of the stag, especially
      Madrepora cervicornis, and Madrepora palmata, of
      Florida and the West Indies.

   Stag-horn fern (Bot.), an Australian and West African fern
      (Platycerium alcicorne) having the large fronds branched
      like a stag's horns; also, any species of the same genus.


   Stag-horn sumac (Bot.), a common American shrub (Rhus
      typhina) having densely velvety branchlets. See Sumac.


   Stag party, a party consisting of men only. [Slang, U. S.]


   Stag tick (Zool.), a parasitic dipterous insect of the
      family Hippoboscidae, which lives upon the stag and is
      usually wingless. The same species lives also upon the
      European grouse, but in that case has wings.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Deer \Deer\ (d[=e]r), n. sing. & pl. [OE. der, deor, animal,
   wild animal, AS. de['o]r; akin to D. dier, OFries. diar, G.
   thier, tier, Icel. d[=y]r, Dan. dyr, Sw. djur, Goth. dius; of
   unknown origin. [root]71.]
   1. Any animal; especially, a wild animal. [Obs.] --Chaucer.
      [1913 Webster]

            Mice and rats, and such small deer.   --Shak.
      [1913 Webster]

            The camel, that great deer.           --Lindisfarne
                                                  MS.
      [1913 Webster]

   2. (Zool.) A ruminant of the genus Cervus, of many species,
      and of related genera of the family Cervid[ae]. The
      males, and in some species the females, have solid
      antlers, often much branched, which are shed annually.
      Their flesh, for which they are hunted, is called
      venison.
      [1913 Webster]

   Note: The deer hunted in England is Cervus elaphus, called
         also stag or red deer; the fallow deer is Cervus
         dama; the common American deer is Cervus
         Virginianus; the blacktailed deer of Western North
         America is Cervus Columbianus; and the mule deer of
         the same region is Cervus macrotis. See Axis,
         Fallow deer, Mule deer, Reindeer.
         [1913 Webster]

   Note: Deer is much used adjectively, or as the first part of
         a compound; as, deerkiller, deerslayer, deerslaying,
         deer hunting, deer stealing, deerlike, etc.
         [1913 Webster]

   Deer mouse (Zool.), the white-footed mouse (Peromyscus
      leucopus, formerly Hesperomys leucopus) of America.

   Small deer, petty game, not worth pursuing; -- used
      metaphorically. (See citation from Shakespeare under the
      first definition, above.) "Minor critics . . . can find
      leisure for the chase of such small deer." --G. P. Marsh.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Elaphine \El"a*phine\, a. [Gr. ? stag.] (Zo["o]l.)
   Pertaining to, resembling, or characteristic of, the stag, or
   Cervus elaphus.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Cervus elaphus
    n 1: common deer of temperate Europe and Asia [syn: red deer,
         elk, American elk, wapiti, Cervus elaphus]