From Middle English bist, beest, best, from Old English bist ("(thou) art"; second person singular of bēon (“to be”)), from Proto-Germanic *biusi (“(thou) art”), equivalent to be + -est. Cognate with West Frisian bist (“(thou) art”), Low German büst (“(thou) art”), German bist (“(thou) art”).
bist - Computer Definition
(Built-In Self Test) A function built into a machine that tests its reliability. Found in integrated circuits (chip), avionics and electronic systems of all types, a BIST may operate only once at startup (see POST) or periodically while the system is running.