Source : Webster's Revised Unabridged Dictionary (1913)

Joint \Joint\ (joint), n. [F. joint, fr. joindre, p. p. joint.
   See {Join}.]
   1. The place or part where two things or parts are joined or
      united; the union of two or more smooth or even surfaces
      admitting of a close-fitting or junction; junction as, a
      joint between two pieces of timber; a joint in a pipe.

   2. A joining of two things or parts so as to admit of motion;
      an articulation, whether movable or not; a hinge; as, the
      knee joint; a node or joint of a stem; a ball and socket
      joint. See {Articulation}.

            A scaly gauntlet now, with joints of steel, Must
            glove this hand.                      --Shak.

            To tear thee joint by joint.          --Milton.

   3. The part or space included between two joints, knots,
      nodes, or articulations; as, a joint of cane or of a grass
      stem; a joint of the leg.

   4. Any one of the large pieces of meat, as cut into portions
      by the butcher for roasting.

   5. (Geol.) A plane of fracture, or divisional plane, of a
      rock transverse to the stratification.

   6. (Arch.) The space between the adjacent surfaces of two
      bodies joined and held together, as by means of cement,
      mortar, etc.; as, a thin joint.

   7. The means whereby the meeting surfaces of pieces in a
      structure are secured together.

   {Coursing joint} (Masonry), the mortar joint between two
      courses of bricks or stones.

   {Fish joint}, {Miter joint}, {Universal joint}, etc. See
      under {Fish}, {Miter}, etc.

   {Joint bolt}, a bolt for fastening two pieces, as of wood,
      one endwise to the other, having a nut embedded in one of
      the pieces.

   {Joint chair} (Railroad), the chair that supports the ends of
      abutting rails.

   {Joint coupling}, a universal joint for coupling shafting.
      See under {Universal}.

   {Joint hinge}, a hinge having long leaves; a strap hinge.

   {Joint splice}, a re["e]nforce at a joint, to sustain the
      parts in their true relation.

   {Joint stool}.
      (a) A stool consisting of jointed parts; a folding stool.
          --Shak.
      (b) A block for supporting the end of a piece at a joint;
          a joint chair.

   {Out of joint}, out of place; dislocated, as when the head of
      a bone slips from its socket; hence, not working well
      together; disordered. ``The time is out of joint.''
      --Shak.

Fish \Fish\, n.; pl. {Fishes}, or collectively, {Fish}. [OE.
   fisch, fisc, fis, AS. fisc; akin to D. visch, OS. & OHG.
   fisk, G. fisch, Icel. fiskr, Sw. & Dan. fisk, Goth. fisks, L.
   piscis, Ir. iasg. Cf. {Piscatorial}. In some cases, such as
   fish joint, fish plate, this word has prob. been confused
   with fish, fr. F. fichea peg.]
   1. A name loosely applied in popular usage to many animals of
      diverse characteristics, living in the water.

   2. (Zo["o]l.) An oviparous, vertebrate animal usually having
      fins and a covering scales or plates. It breathes by means
      of gills, and lives almost entirely in the water. See
      {Pisces}.

   Note: The true fishes include the Teleostei (bony fishes),
         Ganoidei, Dipnoi, and Elasmobranchii or Selachians
         (sharks and skates). Formerly the leptocardia and
         Marsipobranciata were also included, but these are now
         generally regarded as two distinct classes, below the
         fishes.

   3. pl. The twelfth sign of the zodiac; Pisces.

   4. The flesh of fish, used as food.

   5. (Naut.)
      (a) A purchase used to fish the anchor.
      (b) A piece of timber, somewhat in the form of a fish,
          used to strengthen a mast or yard.

   Note: Fish is used adjectively or as part of a compound word;
         as, fish line, fish pole, fish spear, fish-bellied.

   {Age of Fishes}. See under {Age}, n., 8.

   {Fish ball}, fish (usually salted codfish) shared fine, mixed
      with mashed potato, and made into the form of a small,
      round cake. [U.S.]

   {Fish bar}. Same as {Fish plate} (below).

   {Fish beam} (Mech.), a beam one of whose sides (commonly the
      under one) swells out like the belly of a fish. --Francis.

   {Fish crow} (Zo["o]l.), a species of crow ({Corvus
      ossifragus}), found on the Atlantic coast of the United
      States. It feeds largely on fish.

   {Fish culture}, the artifical breeding and rearing of fish;
      pisciculture.

   {Fish davit}. See {Davit}.

   {Fish day}, a day on which fish is eaten; a fast day.

   {Fish duck} (Zo["o]l.), any species of merganser.

   {Fish fall}, the tackle depending from the fish davit, used
      in hauling up the anchor to the gunwale of a ship.

   {Fish garth}, a dam or weir in a river for keeping fish or
      taking them easily.

   {Fish glue}. See {Isinglass}.

   {Fish joint}, a joint formed by a plate or pair of plates
      fastened upon two meeting beams, plates, etc., at their
      junction; -- used largely in connecting the rails of
      railroads.

   {Fish kettle}, a long kettle for boiling fish whole.

   {Fish ladder}, a dam with a series of steps which fish can
      leap in order to ascend falls in a river.

   {Fish line}, or {Fishing line}, a line made of twisted hair,
      silk, etc., used in angling.

   {Fish louse} (Zo["o]l.), any crustacean parasitic on fishes,
      esp. the parasitic Copepoda, belonging to {Caligus},
      {Argulus}, and other related genera. See {Branchiura}.

   {Fish maw} (Zo["o]l.), the stomach of a fish; also, the air
      bladder, or sound.

   {Fish meal}, fish desiccated and ground fine, for use in
      soups, etc.

   {Fish oil}, oil obtained from the bodies of fish and marine
      animals, as whales, seals, sharks, from cods' livers, etc.
      

   {Fish owl} (Zo["o]l.), a fish-eating owl of the Old World
      genera {Scotopelia} and {Ketupa}, esp. a large East Indian
      species ({K. Ceylonensis}).

   {Fish plate}, one of the plates of a fish joint.

   {Fish pot}, a wicker basket, sunk, with a float attached, for
      catching crabs, lobsters, etc.

   {Fish pound}, a net attached to stakes, for entrapping and
      catching fish; a weir. [Local, U.S.] --Bartlett.

   {Fish slice}, a broad knife for dividing fish at table; a
      fish trowel.

   {Fish slide}, an inclined box set in a stream at a small
      fall, or ripple, to catch fish descending the current.
      --Knight.

   {Fish sound}, the air bladder of certain fishes, esp. those
      that are dried and used as food, or in the arts, as for
      the preparation of isinglass.

   {Fish story}, a story which taxes credulity; an extravagant
      or incredible narration. [Colloq. U.S.] --Bartlett.

   {Fish strainer}.
      (a) A metal colander, with handles, for taking fish from a
          boiler.
      (b) A perforated earthenware slab at the bottom of a dish,
          to drain the water from a boiled fish.

   {Fish trowel}, a fish slice.

   {Fish} {weir or wear}, a weir set in a stream, for catching
      fish.

   {Neither fish nor flesh} (Fig.), neither one thing nor the
      other.

Source : WordNet®

fish joint
     n : a butt joint formed by bolting fish plates to the sides of
         two rails or beams