warrant, in law, written order by an official of a court directed to an officer. The search warrant and the warrant of arrest are the most frequently used types. Warrants of attachment order the seizure of a defendant's goods pending trial or judicial determination of ownership and in certain other cases. Warrants are usually issued by a judge or court clerk. They are directed to sheriffs, marshals, constables, and other officers of the peace. The strictest compliance with legal forms and rules for serving a warrant is ordinarily necessary if it is to be effective.