Source : Webster's Revised Unabridged Dictionary (1913)

   7. (Mach.) A joint or other connection uniting parts of
      machinery, or the like, as the elastic pipe of a tender
      connecting it with the feed pipe of a locomotive engine;
      especially, a pipe fitting for connecting pipes, or pipes
      and fittings, in such a way as to facilitate
      disconnection.

   8. (Brewing) A cask suspended on trunnions, in which
      fermentation is carried on.

   {Hypostatic union} (Theol.) See under {Hypostatic}.

   {Latin union}. See under {Latin}.

   {Legislative Union} (Eng. Hist.), the union of Great Britain
      and Ireland, which took place Jan. 1, 1801.

   {Union}, or {Act of Union} (Eng. Hist.), the act by which
      Scotland was united to England, or by which the two
      kingdoms were incorporated into one, in 1707.

   {Union by the first}, or {second}, {intention}. (Surg.) See
      {To heal by the first, or second, intention}, under
      {Intention}.

   {Union down} (Naut.), a signal of distress at sea made by
      reversing the flag, or turning its union downward.

   {Union jack}. (Naut.) See {Jack}, n., 10.

   {Union joint}. (Mech.)
      (a) A joint formed by means of a union.
      (b) A piece of pipe made in the form of the letter T.

   Syn: Unity; junction; connection; concord; alliance;
        coalition; combination; confederacy.

   Usage: {Union}, {Unity}. Union is the act of bringing two or
          more things together so as to make but one, or the
          state of being united into one. Unity is a state of
          simple oneness, either of essence, as the unity of
          God, or of action, feeling, etc., as unity of design,
          of affection, etc. Thus, we may speak of effecting a
          union of interests which shall result in a unity of
          labor and interest in securing a given object.

                One kingdom, joy, and union without end.
                                                  --Milton.

                [Man] is to . . . beget Like of his like, his
                image multiplied. In unity defective; which
                requires Collateral love, and dearest amity.
                                                  --Milton.