\Tack\, n. [From an old or dialectal form of F. tache. See
{Techy}.]
1. A stain; a tache. [Obs.]
2. [Cf. L. tactus.] A peculiar flavor or taint; as, a musty
   tack. [Obs. or Colloq.] --Drayton.

\Tack\, n. [OE. tak, takke, a fastening; akin to D. tak a
branch, twig, G. zacke a twig, prong, spike, Dan. takke a
tack, spike; cf. also Sw. tagg prickle, point, Icel. t[=a]g a
willow twig, Ir. taca a peg, nail, fastening, Gael. tacaid,
Armor. & Corn. tach; perhaps akin to E. take. Cf. {Attach},
{Attack}, {Detach}, {Tag} an end, {Zigzag}.]
1. A small, short, sharp-pointed nail, usually having a
   broad, flat head.
2. That which is attached; a supplement; an appendix. See
   {Tack}, v. t., 3. --Macaulay.
         Some tacks had been made to money bills in King
         Charles's time.                       --Bp. Burnet.
3. (Naut.)
   (a) A rope used to hold in place the foremost lower
       corners of the courses when the vessel is closehauled
       (see Illust. of {Ship}); also, a rope employed to pull
       the lower corner of a studding sail to the boom.
   (b) The part of a sail to which the tack is usually
       fastened; the foremost lower corner of fore-and-aft
       sails, as of schooners (see Illust. of {Sail}).
   (c) The direction of a vessel in regard to the trim of her
       sails; as, the starboard tack, or port tack; -- the
       former when she is closehauled with the wind on her
       starboard side; hence, the run of a vessel on one
       tack; also, a change of direction.
4. (Scots Law) A contract by which the use of a thing is set,
   or let, for hire; a lease. --Burrill.
5. Confidence; reliance. [Prov. Eng.] --Halliwell.
{Tack of a flag} (Naut.), a line spliced into the eye at the
   foot of the hoist for securing the flag to the halyards.
{Tack pins} (Naut.), belaying pins; -- also called {jack
   pins}.
{To haul the tacks aboard} (Naut.), to set the courses.
{To hold tack}, to last or hold out. --Milton.

\Tack\, v. t. [imp. & p. p. {Tacked}; p. pr. & vb. n.
{Tacking}.] [Cf. OD. tacken to touch, take, seize, fix, akin
to E. take. See {Tack} a small nail.]
1. To fasten or attach. ``In hopes of getting some commendam
   tacked to their sees.'' --Swift.
         And tacks the center to the sphere.   --Herbert.
2. Especially, to attach or secure in a slight or hasty
   manner, as by stitching or nailing; as, to tack together
   the sheets of a book; to tack one piece of cloth to
   another; to tack on a board or shingle; to tack one piece
   of metal to another by drops of solder.
3. In parliamentary usage, to add (a supplement) to a bill;
   to append; -- often with on or to. --Macaulay.
4. (Naut.) To change the direction of (a vessel) when sailing
   closehauled, by putting the helm alee and shifting the
   tacks and sails so that she will proceed to windward
   nearly at right angles to her former course.
Note: In tacking, a vessel is brought to point at first
      directly to windward, and then so that the wind will
      blow against the other side.

\Tack\, v. i. (Naut.)
To change the direction of a vessel by shifting the position
of the helm and sails; also (as said of a vessel), to have
her direction changed through the shifting of the helm and
sails. See {Tack}, v. t., 4.
      Monk, . . . when he wanted his ship to tack to
      larboard, moved the mirth of his crew by calling out,
      ``Wheel to the left.''                   --Macaulay.