Source : Webster's Revised Unabridged Dictionary (1913)

Couple \Cou"ple\, v. t. [imp. & p. p. {Coupled} (k?p"'ld); p.
   pr. & vb. n. {Coupling} (-l?ng).] [F. coupler, fr. L.
   copulare. See {Couple}, n., and cf. {Copulate}, {Cobble}, v.]
   1. To link or tie, as one thing to another; to connect or
      fasten together; to join.

            Huntsman, I charge thee, tender well my hounds, . .
            . And couple Clowder with the deep-mouthed brach.
                                                  --Shak.

   2. To join in wedlock; to marry. [Colloq.]

            A parson who couples all our beggars. --Swift.

Coupling \Coup"ling\ (-l?ng), n.
   1. The act of bringing or coming together; connection; sexual
      union.

   2. (Mach.) A device or contrivance which serves to couple or
      connect adjacent parts or objects; as, a belt coupling,
      which connects the ends of a belt; a car coupling, which
      connects the cars in a train; a shaft coupling, which
      connects the ends of shafts.

   {Box coupling}, {Chain coupling}. See under {Box}, Chain.

   {Coupling box}, a coupling shaped like a journal box, for
      clamping together the ends of two shafts, so that they may
      revolve together.

   {Coupling pin}, a pin or bolt used in coupling or joining
      together railroad cars, etc.

Source : WordNet®

coupling
     n 1: a connection (like a clamp or vise) between two things so
          they move together [syn: {yoke}]
     2: a mechanical device that serves to connect the ends of
        adjacent objects [syn: {coupler}]
     3: the act of pairing a male and female for reproductive
        purposes; "the casual couplings of adolescents"; "the
        mating of some species occurs only in the spring" [syn: {mating},
         {pairing}, {conjugation}, {union}, {sexual union}]

Source : Free On-Line Dictionary of Computing

coupling
     
         The degree to which components depend
        on one another.  There are two types of coupling, "tight" and
        "loose".  Loose coupling is desirable for good {software
        engineering} but tight coupling may be necessary for maximum
        performance.  Coupling is increased when the data exchanged
        between components becomes larger or more complex.
     
        (1996-08-01)