The Collaborative International Dictionary of English v.0.48:

Worse \Worse\, n.
   1. Loss; disadvantage; defeat. "Judah was put to the worse
      before Israel." --Kings xiv. 12.
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   2. That which is worse; something less good; as, think not
      the worse of him for his enterprise.
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The Collaborative International Dictionary of English v.0.48:

Worse \Worse\, adv. [AS. wiers, wyrs; akin to OS. & OHG. wirs,
   Icel. verr, Goth, wa['i]rs; a comparative adverb with no
   corresponding positive. See Worse, a.]
   In a worse degree; in a manner more evil or bad.
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         Now will we deal worse with thee than with them. --Gen.
                                                  xix. 9.
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The Collaborative International Dictionary of English v.0.48:

Worse \Worse\, a., compar. of Bad. [OE. werse, worse, wurse,
   AS. wiersa, wyrsa, a comparative with no corresponding
   positive; akin to OS. wirsa, OFries. wirra, OHG. wirsiro,
   Icel. verri, Sw. v[aum]rre, Dan. v[aum]rre, Goth.
   wa['i]rsiza, and probably to OHG. werran to bring into
   confusion, E. war, and L. verrere to sweep, sweep along. As
   bad has no comparative and superlative, worse and worst are
   used in lieu of them, although etymologically they have no
   relation to bad.]
   Bad, ill, evil, or corrupt, in a greater degree; more bad or
   evil; less good; specifically, in poorer health; more sick;
   -- used both in a physical and moral sense.
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         Or worse, if men worse can devise.       --Chaucer.
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         [She] was nothing bettered, but rather grew worse.
                                                  --Mark v. 26.
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         Evil men and seducers shall wax worse and worse. --2
                                                  Tim. iii. 13.
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         There are men who seem to believe they are not bad
         while another can be found worse.        --Rambler.
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         "But I love him." "Love him? Worse and worse." --Gay.
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The Collaborative International Dictionary of English v.0.48:

Worse \Worse\, v. t. [OE. wursien, AS. wyrsian to become worse.]
   To make worse; to put disadvantage; to discomfit; to worst.
   See Worst, v.
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         Weapons more violent, when next we meet,
         May serve to better us and worse our foes. --Milton.
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The Collaborative International Dictionary of English v.0.48:

Bad \Bad\ (b[a^]d), a. [Compar. Worse (w[^u]s); superl.
   Worst (w[^u]st).] [Probably fr. AS. b[ae]ddel
   hermaphrodite; cf. b[ae]dling effeminate fellow.]
   Wanting good qualities, whether physical or moral; injurious,
   hurtful, inconvenient, offensive, painful, unfavorable, or
   defective, either physically or morally; evil; vicious;
   wicked; -- the opposite of good; as, a bad man; bad
   conduct; bad habits; bad soil; bad air; bad health; a bad
   crop; bad news.

   Note: Sometimes used substantively.
         [1913 Webster]

               The strong antipathy of good to bad. --Pope.
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   Syn: Pernicious; deleterious; noxious; baneful; injurious;
        hurtful; evil; vile; wretched; corrupt; wicked; vicious;
        imperfect.
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WordNet (r) 3.0 (2006):

worse
    adv 1: (comparative of `ill') in a less effective or successful
           or desirable manner; "he did worse on the second exam"
    adj 1: (comparative of `bad') inferior to another in quality or
           condition or desirability; "this road is worse than the
           first one we took"; "the road is in worse shape than it
           was"; "she was accused of worse things than cheating and
           lying" [ant: better]
    2: changed for the worse in health or fitness; "I feel worse
       today"; "her cold is worse" [syn: worse, worsened] [ant:
       better]
    n 1: something inferior in quality or condition or effect; "for
         better or for worse"; "accused of cheating and lying and
         worse"

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "worse":
   aggravated, altered, amplified, annoyed, augmented, better, broken,
   burned, burst, busted, changeable, changed, checked, chipped,
   converted, cracked, crazed, cut, damaged, degenerate,
   deliberately provoked, deteriorated, deviant, divergent,
   embittered, enhanced, enlarged, exacerbated, exasperated, harmed,
   heated up, heightened, hotted up, hurt, impaired, imperfect,
   improved, in bits, in pieces, in shards, increased, injured,
   intensified, irritated, lacerated, magnified, mangled,
   metamorphosed, metastasized, modified, mutant, mutilated, provoked,
   qualified, rebuilt, reformed, renewed, rent, revived,
   revolutionary, ruptured, scalded, scorched, shattered, slashed,
   slit, smashed, soured, split, sprung, subversive, the worse for,
   torn, transformed, translated, transmuted, unmitigated, weakened,
   worse off, worsened