white out (Noun) — An arctic atmospheric condition with clouds over snow produce a uniform whiteness and objects are difficult to see; occurs when the light reflected off the snow equals the light coming through the clouds.
white out (Verb) — Cover up with a liquid correction fluid.
white out (Verb) — (printing) widen the interlinear spacing by inserting leads.
white out (Verb) — Lose daylight visibility in heavy fog, snow, or rain.