THESAURUS
flat out
a outrance, a toute outrance, absolute, absolutely, admitting no exception, all hollow, all out, all the way, all-out, apace, at full blast, at full drive, at full speed, at full throttle, beyond all bounds, beyond compare, beyond comparison, beyond measure, blasted, categorical, clear, complete, completely, conclusive, damned, dead, decided, decisive, definite, definitive, determinate, downright, entire, essentially, expeditiously, explicit, express, extremely, final, fixed, flat, flat-out, full speed ahead, fundamentally, global, hastily, immeasurably, implicit, in excess, in full sail, in the extreme, inappealable, incalculably, indefinitely, indisputable, infinitely, lickety-split, most, out-and-out, outright, peremptory, perfect, perfectly, positive, posthaste, purely, quickly, radically, rank, rapidly, round, speedily, straight, straight-out, swiftly, to a fare-you-well, to a fault, to excess, to extremes, to the backbone, to the extreme, to the full, to the limit, to the marrow, to the skies, to the sky, to the utmost, too far, total, totally, uncircumscribed, unconditional, unconditionally, unconditioned, under full steam, undoubting, unequivocal, unequivocally, unhampered, unhesitating, unlimited, unmistakable, unmitigated, unqualified, unquestioning, unreserved, unrestricted, unwaivable, utter, utterly, whole, wide open, with a vengeance, with all speed, without exception, without reserve
ROGET THESAURUS
flat out
Failure
VB
fail, be unsuccessful, not succeed, make vain efforts, do in vain, labor in vain, toil in vain, flunk, lose one's labor, take nothing by one's motion, bring to naught, make nothing of, wash a blackamoor white, roll the stones of Sisyphus, do by halves, lose ground, fall short of, miss, miss one's aim, miss the mark, miss one's footing, miss stays, slip, trip, stumble, make a slip, blunder, make a mess of, make a botch of, bitch it, miscarry, abort, go up like a rocket and come down like the stick, come down in flames, get shot down, reckon without one's host, get the wrong pig by the tail, get the wrong sow by the ear, limp, halt, hobble, titubate, fall, tumble, lose one's balance, fall to the ground, fall between two stools, flounder, falter, stick in the mud, run aground, split upon a rock, beat one's head against a stone wall, run one's head against a stone wall, knock one's head against a stone wall, dash one's head against a stone wall, break one's back, break down, sink, drown, founder, have the ground cut from under one, get into trouble, get into a mess, get into a scrape, come to grief, go to the wall, go to the dogs, go to pot, lick the dust, bite the dust, be defeated, have the worst of it, lose the day, come off second best, lose, fall a prey to, succumb, not have a leg to stand on, come to nothing, end in smoke,
flat out, fall to the ground, fall through, fall dead, fall stillborn, fall flat, slip through one's fingers, hang fire, miss fire, flash in the pan, collapse, topple down, go to wrack and ruin, go amiss, go wrong, go cross, go hard with, go on a wrong tack, go on ill, come off ill, turn out ill, work ill, take a wrong term, take an ugly term, take an ugly turn, take a turn for the worse, be all over with, be all up with, explode, dash one's hopes, defeat the purpose, sow the wind and reap the whirlwind, jump out of the frying pan into the fire, go from the frying pan into the fire.
Shortcoming
VB
come short of, fall short of, stop short of, come short, fall short, stop short, not reach, want, keep within bounds, keep within the mark, keep within the compass, break down, stick in the mud, collapse,
flat out, come to nothing, fall through, fall to the ground, cave in, end in smoke, miss the mark, fail, lose ground, miss stays.
