Synonyms for Worst:

adj.

most wanting (adjective)
inferior, least, lowest.

n.

least, meanest, least effective, least meaningful, least understanding, most ghastly, most harmful, most horrible, most pitiful. best. ace, lick, master, rout, subdue, subjugate, surmount, trim, win, triumph over, go someone one better. worse (noun)
degenerate, extraordinary, impoverished, inferior, pale, retrogressive, worse, for the worse, worst of all.
worst (noun)
bottom, last, last-place, lowest, mop up, most evil, most unattractive, most undesirable, most unpleasant, most unsuitable, most wicked, pessimal, pessimum, pip, poorest, rack up, whip.

v.

competition (verb)
mop up, pip, rack up, whip.

Other synonyms:

lick. subdue, trim. worse
degenerate, impoverished, inferior, pale, retrogressive, worse.
Other relevant words:
ace, inferior, lick, master, pale, rout, subdue, subjugate, surmount, trim, win, worse, triumph over, go someone one better, most horrible.

Usage examples for worst

  1. The worst was when I heard you had been put on the case- no, that wasn't the worst – The Woman in Black by Edmund Clerihew Bentley
  2. But that isn't the worst – Just Patty by Jean Webster
  3. But the worst thing of all was that Peter was lost, had been lost for three days, and now they felt they must give up hope. – Penny Plain by Anna Buchan (writing as O. Douglas)