Merriam-Webster Collegiate Dictionary - worst

 I. adjective, superlative of bad or of ill  Etymology: Middle English werste, ~e, from Old English wierresta, wyrsta, superlative of the root of Old English wiersa worse  Date: before 12th century  1. most corrupt, bad, evil, or ill his ~ fault  2.  a. most unfavorable, difficult, unpleasant, or painful the ~ news your ~ enemy  b. most unsuitable, faulty, unattractive, or ill-conceived has the ~ table manners  c. least skillful or efficient the ~ person for the job  3. most wanting in quality, value, or condition the ~ results  II. adverb, superlative of ill or illy or of bad or badly  Date: before 12th century  1. to the extreme degree of badness or inferiority the ~ dressed person  2. to the greatest or highest degree groups who need the subsidies ~ lose out — T. W. Arnold  III. noun  (plural ~)  Date: 13th century one that is ~  IV. transitive verb  Date: 1636 to get the better of ; defeat