What is "picketpin"

Picket \Pick"et\, n. [F. piquet, properly dim. of pique spear, pike. See Pike, and cf. Piquet.]

1. A stake sharpened or pointed, especially one used in fortification and encampments, to mark bounds and angles; or one used for tethering horses.

2. A pointed pale, used in marking fences.

3. [Probably so called from the picketing of the horses.] (Mil.) A detached body of troops serving to guard an army from surprise, and to oppose reconnoitering parties of the enemy; -- called also outlying picket.

4. By extension, men appointed by a trades union, or other labor organization, to intercept outsiders, and prevent them from working for employers with whom the organization is at variance. [Cant]

5. A military punishment, formerly resorted to, in which the offender was forced to stand with one foot on a pointed stake.

6. A game at cards. See Piquet. Inlying picket (Mil.), a detachment of troops held in camp or quarters, detailed to march if called upon. Picket fence, a fence made of pickets. See def. 2, above. Picket guard (Mil.), a guard of horse and foot, always in readiness in case of alarm. Picket line. (Mil.)

   1. A position held and guarded by small bodies of men placed at intervals.

   2. A rope to which horses are secured when groomed.

      Picketpin, an iron pin for picketing horses.