The Collaborative International Dictionary of English v.0.48:

Couple \Cou"ple\, v. t. [imp. & p. p. Coupled (k[u^]p"'ld); p.
   pr. & vb. n. Coupling (k[u^]p"l[i^]ng).] [F. coupler, fr.
   L. copulare. See Couple, n., and cf. Copulate, Cobble,
   v.]
   [1913 Webster]
   1. To link or tie, as one thing to another; to connect or
      fasten together; to join.
      [1913 Webster]

            Huntsman, I charge thee, tender well my hounds, . .
            .
            And couple Clowder with the deep-mouthed brach.
                                                  --Shak.
      [1913 Webster]

   2. To join in wedlock; to marry. [Colloq.]
      [1913 Webster]

            A parson who couples all our beggars. --Swift.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Coupling \Coup"ling\ (-l?ng), n.
   1. The act of bringing or coming together; connection; sexual
      union.
      [1913 Webster]

   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.
      [1913 Webster]

   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.
      [1913 Webster]

WordNet (r) 3.0 (2006):

coupling
    n 1: a connection (like a clamp or vise) between two things so
         they move together [syn: yoke, coupling]
    2: a mechanical device that serves to connect the ends of
       adjacent objects [syn: coupling, 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: coupling,
       mating, pairing, conjugation, union, sexual union]

Moby Thesaurus II by Grady Ward, 1.0:

85 Moby Thesaurus words for "coupling":
   agglomeration, agglutination, aggregation, ankle, articulation,
   bond, boundary, bracketing, butt, cervix, clinch, closure,
   clustering, combination, communication, concatenation, concourse,
   concurrence, confluence, congeries, conglomeration, conjugation,
   conjunction, connecting link, connecting rod, connection,
   convergence, copulation, dovetail, elbow, embrace, gathering,
   gliding joint, hinge, hinged joint, hip, hookup,
   intercommunication, intercourse, interface, interlinking, join,
   joinder, joining, joint, jointure, junction, juncture, knee,
   knotting, knuckle, liaison, link, linkage, linking, marriage,
   meeting, merger, merging, miter, mortise, neck, pairing, pivot,
   pivot joint, rabbet, scarf, seam, shoulder, splice, stitch, suture,
   symbiosis, symphysis, tie, tie rod, tie-in, tie-up, toggle,
   toggle joint, unification, union, weld, wrist, yoking



The Free On-line Dictionary of Computing (30 December 2018):

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)