memory device consisting of a long thin plastic strip coated with iron oxide; used to record audio or video signals or to store computer information; "he took along a dozen tapes to record the interview"
a measuring instrument that sends out an acoustic pulse in water and measures distances in terms of the time for the echo of the pulse to return; "sonar is an acronym for sound navigation ranging"; "asdic is an acronym for antisubmarine detection investigation committee"