SUDDENLY

adv. 1 in a flash or a moment or a split second, all at once, instantly, instantaneously, momentarily, fleetingly, in the twinkling of an eye, in a trice; quickly, abruptly, swiftly, speedily, rapidly Suddenly, my whole life flashed before me He suddenly realized why the head of MI6 had summoned him. 2 all of a sudden, out of the blue, unexpectedly, without warning, on the spur of the moment, hastily, hurriedly, feverishly Suddenly, she turned on her heel and stormed out