worse (adj.)

Old English wiersa, wyrsa "worse," from Proto-Germanic *wers-izon- (source also of Old Saxon wirs, Old Norse verri, Swedish värre, Old Frisian wirra, Old High German wirsiro, Gothic wairsiza "worse"), comparative of PIE *wers- (1) "to confuse, mix up" (source also of Old High German werra "strife," Old Saxon werran "to entangle, compound;" see war (n.)). Used as a comparative of bad, evil, ill or as the opposite of better. The adverb is Old English wyrs; the noun is Old English wyrsa. Phrase for better or for worse is attested from late 14c. (for bet, for wers); to change for the worse is recorded from c. 1400.

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