The Collaborative International Dictionary of English v.0.48:

Tail \Tail\, n. [AS. taegel, taegl; akin to G. zagel, Icel.
   tagl, Sw. tagel, Goth. tagl hair. [root]59.]
   1. (Zool.) The terminal, and usually flexible, posterior
      appendage of an animal.
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   Note: The tail of mammals and reptiles contains a series of
         movable vertebrae, and is covered with flesh and hairs
         or scales like those of other parts of the body. The
         tail of existing birds consists of several more or less
         consolidated vertebrae which supports a fanlike group
         of quills to which the term tail is more particularly
         applied. The tail of fishes consists of the tapering
         hind portion of the body ending in a caudal fin. The
         term tail is sometimes applied to the entire abdomen of
         a crustacean or insect, and sometimes to the terminal
         piece or pygidium alone.
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   2. Any long, flexible terminal appendage; whatever resembles,
      in shape or position, the tail of an animal, as a catkin.
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            Doretus writes a great praise of the distilled
            waters of those tails that hang on willow trees.
                                                  --Harvey.
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   3. Hence, the back, last, lower, or inferior part of
      anything, -- as opposed to the head, or the superior
      part.
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            The Lord will make thee the head, and not the tail.
                                                  --Deut.
                                                  xxviii. 13.
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   4. A train or company of attendants; a retinue.
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            "Ah," said he, "if you saw but the chief with his
            tail on."                             --Sir W.
                                                  Scott.
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   5. The side of a coin opposite to that which bears the head,
      effigy, or date; the reverse; -- rarely used except in the
      expression "heads or tails," employed when a coin is
      thrown up for the purpose of deciding some point by its
      fall.
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   6. (Anat.) The distal tendon of a muscle.
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   7. (Bot.) A downy or feathery appendage to certain achenes.
      It is formed of the permanent elongated style.
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   8. (Surg.)
      (a) A portion of an incision, at its beginning or end,
          which does not go through the whole thickness of the
          skin, and is more painful than a complete incision; --
          called also tailing.
      (b) One of the strips at the end of a bandage formed by
          splitting the bandage one or more times.
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   9. (Naut.) A rope spliced to the strap of a block, by which
      it may be lashed to anything.
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   10. (Mus.) The part of a note which runs perpendicularly
       upward or downward from the head; the stem. --Moore
       (Encyc. of Music).
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   11. pl. Same as Tailing, 4.
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   12. (Arch.) The bottom or lower portion of a member or part,
       as a slate or tile.
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   13. pl. (Mining) See Tailing, n., 5.
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   14. (Astronomy) the long visible stream of gases, ions, or
       dust particles extending from the head of a comet in the
       direction opposite to the sun.
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   15. pl. (Rope Making) In some forms of rope-laying machine,
       pieces of rope attached to the iron bar passing through
       the grooven wooden top containing the strands, for
       wrapping around the rope to be laid.
       [Webster 1913 Suppl.]

   16. pl. A tailed coat; a tail coat. [Colloq. or Dial.]
       [Webster 1913 Suppl.]

   17. (Aeronautics) In airplanes, an airfoil or group of
       airfoils used at the rear to confer stability.
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   18. the buttocks. [slang or vulgar]
       [PJC]

   19. sexual intercourse, or a woman used for sexual
       intercourse; as, to get some tail; to find a piece of
       tail. See also tailing[3]. [slang and vulgar]
       [PJC]

   Tail beam. (Arch.) Same as Tailpiece.

   Tail coverts (Zool.), the feathers which cover the bases of
      the tail quills. They are sometimes much longer than the
      quills, and form elegant plumes. Those above the quills
      are called the upper tail coverts, and those below, the
      under tail coverts.

   Tail end, the latter end; the termination; as, the tail end
      of a contest. [Colloq.]

   Tail joist. (Arch.) Same as Tailpiece.

   Tail of a comet (Astron.), a luminous train extending from
      the nucleus or body, often to a great distance, and
      usually in a direction opposite to the sun.

   Tail of a gale (Naut.), the latter part of it, when the
      wind has greatly abated. --Totten.

   Tail of a lock (on a canal), the lower end, or entrance
      into the lower pond.

   Tail of the trenches (Fort.), the post where the besiegers
      begin to break ground, and cover themselves from the fire
      of the place, in advancing the lines of approach.

   Tail spindle, the spindle of the tailstock of a turning
      lathe; -- called also dead spindle.

   To turn tail, to run away; to flee.
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            Would she turn tail to the heron, and fly quite out
            another way; but all was to return in a higher
            pitch.                                --Sir P.
                                                  Sidney.
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