Definition of "picket"

picket

/ˈpɪkɪt/

noun
countable and uncountable, plural pickets
1. A stake driven into the ground.
2. (historical) A type of punishment by which an offender had to rest his or her entire body weight on the top of a small stake.
3. A tool in mountaineering that is driven into the snow and used as an anchor or to arrest falls.
4. (military) One of the soldiers or troops placed on a line forward of a position to warn against an enemy advance; or any unit (for example, an aircraft or ship) performing a similar function.
  Quotations
  So confident was he that he ignored the warning of his two British advisers to post pickets to watch the river, and even withdrew those they had placed there.
  1990, Peter Hopkirk, The Great Game, Folio Society, published 2010, page 59
5. (sometimes figurative) A sentry.
  Quotations
  Maccario, it was evident, did not care to take the risk of blundering upon a picket, and a man led them by twisting paths until at last the hacienda rose blackly before them.
  1907, Harold Bindloss, chapter 26, in The Dust of Conflict
6. A protester positioned outside an office, workplace etc. during a strike (usually in plural); also the protest itself.
  Quotations
  In the autumn there was a row at some cement works about the unskilled labour men. A union had just been started for them and all but a few joined. One of these blacklegs was laid for by a picket and knocked out of time.
  1918, W[illiam] B[abington] Maxwell, chapter XXII, in The Mirror and the Lamp, Indianapolis, Ind.: The Bobbs-Merrill Company
7. (card games, uncountable) The card game piquet.
verb
third-person singular simple present pickets, present participle picketing, simple past and past participle picketed
1. (intransitive) To protest, organized by a labour union, typically in front of the location of employment.
2. (transitive) To enclose or fortify with pickets or pointed stakes.
3. (transitive) To tether to, or as if to, a picket.
4. (transitive) To guard, as a camp or road, by an outlying picket.
5. (obsolete, transitive) To torture by forcing to stand with one foot on a pointed stake.