picket

A pointed stake often driven into the ground to support a fence, secure a tent, tether animals, mark points in surveying, or, when pointed at the top, serve as a defense.

A detachment of one or more troops, ships, or aircraft held in readiness or advanced to warn of an enemy’s approach.

A person or group of persons stationed outside a place of employment, usually during a strike, to express grievance or protest and discourage entry by nonstriking employees or customers.

A person or group of persons present outside a building to protest.

To enclose, secure, tether, mark out, or fortify with pickets.

To post as a picket.

To guard with a picket.

To post a picket or pickets during a strike or demonstration.