pinger
- n a pulse generator used for echo sounding in sonar
- The electronic homing pinger was reportedly missing from one box and the pinger on the other was operational but apparently shielded, complicating the recovery effort.
- Three hundred feet up its cable it carried a "pinger," whose sound could be detected by the Chain four miles above.
- Weekends, he uses his own underwater sonic pinger for a scientist's hobby: probing Boston's Charles River for an 800-year-old Viking ship that he believes may lie on the bottom.