ping·er 
(pĭngər)
(pĭngər)n.
A device used underwater to produce pulses of sound, as for an echo sounder or a locator device.
- instructorship
- instrument
- instrumental
- instrumentalism
- instrumentalist
- instrumentality
- instrumentally
- instrumentation
- instrument flying
- instrument landing
- instrument panel
- insubordinate
- insubordinately
- insubordination
- insubstantial
- insubstantiality
- insufferable
- insufferably
- insufficiency
- insufficient
- insufficiently
- insufflate
- insufflation
- insufflator
- insula