We’ve all heard of picket lines, where protesting workers carrying placards attempt to blockade entry to a workplace. It is tempting to think that this term must derive from the wooden stakes that these signs are attached to, but this does not appear to be the case.
The word picket indeed derives from the French word for a pointed stake, piquet, which is how the word was spelled in early usage. It carried the same meaning in English, and rows of pickets used to build fortifications or fences were also called pickets (although today we call them “picket fences”). This led to usage of the term to describe a small detachment of troops, probably due to their similar function of providing a barrier of protection. It is this sense of the term that carried over to the present day association with lines of workers barricading a workplace, resembling a human fence. The fact that they may also be carrying signs attached to a picket would seem to be a convenient coincidence.
In the seventeenth and eighteenth centuries, a picket was also a form of military punishment wherein the perpetrator was forced to stand on one foot on top of a pointed stake driven into the ground. That’s gotta hurt!