tack

Concise Oxford English Dictionary © 2008 Oxford University Press:
tack1

▶noun

• 1 a small, sharp broad-headed nail.

  ■ N. Amer. a drawing pin.

• 2 a long stitch used to fasten fabrics together temporarily, prior to permanent sewing.

• 3 a course of action: there is no reason for them to change tack now.

• 4 Sailing an act of tacking.

  ■ a boat's course relative to the direction of the wind.

• 5 Sailing a rope for securing the corner of certain sails.

  ■ the corner to which such a rope is fastened.

• 6 the quality of being sticky.

▶verb

• 1 fasten or fix with tacks or with temporary long stitches.

• 2 (tack something on) add something to something already existing.

• 3 Sailing change course by turning a boat's head into and through the wind.

  ■ make a series of such changes of course.

– derivatives
tacker noun.

– origin ME: prob. rel. to OFr. tache ‘clasp, large nail’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
tack2

▶noun equipment used in horse riding, including the saddle and bridle.

– origin C18 (in the sense ‘apparatus, equipment’): contr. of tackle.

Concise Oxford English Dictionary © 2008 Oxford University Press:
tack3

▶noun informal cheap, shoddy, or tasteless material.

– origin 1980s: back-form. from tacky2.