(slang) A hidden listening device on the person of an undercover operative for the purposes of obtaining incriminating spoken evidence.
(informal) A deadline or critical endpoint.
(billiards) A wire strung with beads and hung horizontally above or near the table which is used to keep score.
(plural) Any of the system of wires used to operate the puppets in a puppet show; hence, the network of hidden influences controlling the action of a person or organization; strings.