From WordNet (r) 3.0 (2006):
picket
n 1: a person employed to keep watch for some anticipated event
[syn: lookout, lookout man, sentinel, sentry,
watch, spotter, scout, picket]
2: a detachment of troops guarding an army from surprise attack
3: a protester posted by a labor organization outside a place of
work
4: a vehicle performing sentinel duty
5: a wooden strip forming part of a fence [syn: picket,
pale]
6: a form of military punishment used by the British in the late
17th century in which a soldier was forced to stand on one
foot on a pointed stake [syn: picket, piquet]
v 1: serve as pickets or post pickets; "picket a business to
protest the layoffs"
2: fasten with a picket; "picket the goat"