zero-dayEnglishMerriam-Webster Dictionary:'>//the fiery crash of two jumbo jet airplanes in midairSynonyms collision, concussion, crack-up, smash, smashup, wreckRelated Words accident, pileupdemolishment, destruction, ruin2 a falling short of one's goals //refused to be discouraged by the crash of her hairdressing businessSynonyms collapse, cropper, defeat, failure, fizzle, nonachievement, nonsuccessRelated Words futility, uselessnessineffectiveness, ineffectuality, ineffectualness, inefficaciousness, inefficacydeficiency, inadequacy, zero-day — MW · Shobdo