To send a signal or make brief contact.\r\n\r\nRecently from computer networking, where one computer (usually a client) will send a quick, pointless query to another computer (usually a server) in order to find out if it is still online and see how long the response takes. \r\n\r\nOriginally from the naval warfare practice of "active sonar" where one ship (usually a surface ship) will send out a given sound or "ping" in order to measure the direction and delay in the "echo" of that sound off of another body (usually a submarine.\n> Can we go to the movie tomorrow?\n> I don't know... Ping me around eight and we'll see how things are going.\n