1.  worst(n = noun.event) - the least favorable outcome; "the worst that could happen"
is a kind of final result, outcome, result, resultant, termination
Derived form adjective worst₁

2.  worst(n = noun.attribute) - the greatest damage or wickedness of which one is capable; "the invaders did their worst"; "so pure of heart that his worst is another man's best"
is a kind of evil, evilness
Derived form adjective worst₁

3.  worst(n = noun.act) - the weakest effort or poorest achievement one is capable of; "it was the worst he had ever done on a test"
is a kind of attempt, effort, endeavor, endeavour, try
Antonym: best
Derived form adjective worst₁

   worst(v = verb.competition) mop up, pip, rack up, whip - defeat thoroughly; "He mopped up the floor with his opponents"
is one way to beat, beat out, crush, shell, trounce, vanquish
Sample sentences: The fighter managed to worst his opponent

   worst(a = adj.all) - (superlative of `bad') most wanting in quality or value or condition; "the worst player on the team"; "the worst weather of the year"
Antonym: best
Derived forms noun worst₃, noun worst₂, noun worst₁

   worst(r = adv.all) - to the highest degree of inferiority or badness; "She suffered worst of all"; "schools were the worst hit by government spending cuts"; "the worst dressed person present"

   Bad, evil, or pernicious, in the highest degree, whether in a physical or moral sense. See Worse. Milton. [1913 Webster]
" I have a wife, the worst that may be." [1913 Webster]
"If thou hadst not been born the worst of men,
Thou hadst been a knave and flatterer." [1913 Webster]

   That which is most bad or evil; the most severe, pernicious, calamitous, or wicked state or degree. [1913 Webster]
"The worst is not
So long as we can say, This is the worst." [1913 Webster]
"He is always sure of finding diversion when the worst comes to the worst." [1913 Webster]

   To gain advantage over, in contest or competition; to get the better of; to defeat; to overthrow; to discomfit. [1913 Webster]
"The . . . Philistines were worsted by the captivated ark." [1913 Webster]

   To grow worse; to deteriorate. Jane Austen. [1913 Webster]

worst, adj., adv., n., & v.
--adj. most bad.
--adv. most badly.
--n. the worst part, event, circumstance, or possibility (the worst of the storm is over; prepare for the worst).
--v.tr. get the better of; defeat, outdo.

Idiom:
at its etc. worst in the worst state. at worst (or the worst) in the worst possible case. do your worst an expression of defiance. get (or have) the worst of it be defeated. if the worst comes to the worst if the worst happens.

Etymology:
OE wierresta, wyrresta (adj.), wyrst, wyrrest (adv.), f. Gmc

VB  succeed, be successful, gain one's end, gain one's ends, crown with success, gain a point, attain a point, carry a point, secure a point, win a point, win an object, get there, manage to, contrive to, accomplish, do wonders, work wonders, make a go of it, come off well, come off successful, come off with flying colors, make short work of, take by storm, carry by storm, bear away the bell, win one's wings, win one's spurs, win the battle, win the day, carry the day, gain the day, gain the prize, gain the palm, have the best of it, have it all one's own way, have the game in one's owns hands, have the ball at one's feet, have one on the hop, walk over the course, carry all before one, remain in possession of the field, score a success, speed, make progress, win one's way, make one's way, work one's way, find one's way, strive to some purpose, prosper, drive a roaring trade, make profit, reap the fruits, gather the fruits, reap the benefit of, reap the harvest, strike oil, gain a windfall, make one's fortune, get in the harvest, turn to good account, turn to account, triumph, be triumphant, gain a victory, obtain a victory, gain an advantage, chain victory to one's car, nail a coonskin to the wall, surmount a difficulty, overcome a difficulty, get over a difficulty, get over an obstacle, se tirer d'affaire, make head against, stem the torrent, stem the tide, stem the current, weather the storm, weather a point, turn a corner, keep one's head above water, tide over, master, get the better of, have the better of, gain the better of, gain the best of, gain the upper hand, gain the ascendancy, gain the whip hand, gain the start of, distance, surpass, defeat, conquer, vanquish, discomfit, euchre, overcome, overthrow, overpower, overmaster, overmatch, overset, override, overreach, outwit, outdo, outflank, outmaneuver, outgeneral, outvote, take the wind out of one's adversary's sails, beat, beat hollow, rout, lick, drub, floor, worst, put down, put to flight, put to the rout, put hors de combat, put out of court, silence, quell, nonsuit, checkmate, upset, confound, nonplus, stalemate, trump, baffle, circumvent, elude, trip up, trip up the heels of, drive into a corner, drive to the wall, run hard, put one's nose out of joint, settle, do for, break the neck of, break the back of, capsize, sink, shipwreck, drown, swamp, subdue, subjugate, reduce, make the enemy bite the dust, victimize, roll in the dust, trample under foot, put an extinguisher upon, answer, answer the purpose, avail, prevail, take effect, do, turn out well, work well, take, tell, bear fruit, hit it, hit the mark, hit the right nail on the head, nick it, turn up trumps, make a hit, find one's account in.

at the worst, at worst