1. A rudimentary form of testing applied to electronic
equipment following repair or reconfiguration, in which power
is applied and the tester checks for sparks, smoke, or other
dramatic signs of fundamental failure. See
magic smoke.
2. By extension, the first run of a piece of software after
construction or a critical change. See and compare
realitycheck.
There is an interesting semi-parallel to this term among
typographers and printers: When new typefaces are being
punch-cut by hand, a "smoke test" (hold the letter in candle
smoke, then press it onto paper) is used to check out new
dies.