Pinger

noun

1. A device that emits a short, high-pitched sound burst, such as in sonar or other echo location systems.

   "We couldn't take the boat into the shallows near the reef because our sonar pinger was broken."

2. A device that periodically emits a signal that can be monitored to permit movement tracking.

   "The scientist attached a pinger to the carapace of the sea turtle to track its migration."

3. A computer program that sends a ping message over a network.

   "Some people like fancy pingers with extra features, but I always use the default ping application."

4. A user of a ping program; one who pings.

   "Every time we replace the main page, we get flooded with pingers making sure our web site is still there."

5. An illicit drug, especially ecstasy, taken for recreational purposes.

   "That was a great party. Everyone took a pinger or two."