1. [n]  a structure consisting of something wound in a continuous series of loops; "a coil of rope"
2. [n]  reactor consisting of a spiral of insulated wire that introduces inductance into a circuit
3. [n]  tubing that is wound in a spiral
4. [n]  a contraceptive device placed inside a woman's womb
5. [n]  a transformer that supplies high voltage to spark plugs in a gasoline engine
6. [n]  a round shape formed by a series of concentric circles
7. [v]  wind around something in coils or loops
8. [v]  make without a wheel; of pottery
9. [v]  to wind or move in a spiral course:" the muscles and nerves of his fine drawn body were coiling for action,", "black smoke coiling up into the sky"; "the young people gyrated on the dance floor"

Coil
Coil

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1. \Coil\ (koil), v. t. [imp. & p. p. {Coiled} (koild); p. pr.
   & vb. n. {Coiling}.] [OF. coillir, F. cueillir, to collect,
   gather together, L. coligere; col- + legere to gather. See
   {Legend}, and cf. {Cull}, v. t., {Collect}.]
   1. To wind cylindrically or spirally; as, to coil a rope when
      not in use; the snake coiled itself before springing.
   2. To encircle and hold with, or as with, coils. [Obs. or R.]
      --T. Edwards.
   

2. \Coil\, v. i.
   To wind itself cylindrically or spirally; to form a coil; to
   wind; -- often with about or around.
         You can see his flery serpents . . . Coiting, playing
         in the water.                            --Longfellow.
   

3. \Coil\, n.
   1. A ring, series of rings, or spiral, into which a rope, or
      other like thing, is wound.
            The wild grapevines that twisted their coils from
            trec to tree.                         --W. Irving.
   2. Fig.: Entanglement; toil; mesh; perplexity.
   3. A series of connected pipes in rows or layers, as in a
      steam heating apparatus.
   {Induction coil}. (Elec.) See under {Induction}.
   {Ruhmkorff's coil} (Elec.), an induction coil, sometimes so
      called from Ruhmkorff, a prominent manufacturer of the
      apparatus.
   

4. \Coil\, n. [Of Celtic origin; cf. Gael. goil fume, rage.]
   A noise, tumult, bustle, or confusion. [Obs.] --Shak.