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.(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.
Picket line. (Mil.) (a)A position held and guarded by small bodies of men placed at intervals.
(b)A rope to which horses are secured when groomed.