noun: A test for leaks involving blowing smoke into a tube or pipe.
noun: A preliminary test on a newly-constructed piece of electronic equipment, consisting simply of the application of electrical power, to make sure that no egregious wiring errors exist which would cause the circuitry to emit smoke, catch fire, explode, etc.
noun: (by extension) Such an initial test on some other (not necessarily electronic) system, such as a computer program, again, not to perform any exhaustive tests of functionality, but simply to make sure that the system will not catastrophically fail on activation.
noun: A test to make sure that theatrical smoke will not set off the smoke alarms in a building.
