WordWeb Online

1. Changed for the worse in health or fitness
   - worse
    
2. Made or become worse; impaired
   "troubled by the worsened economic conditions"; "the worsened diplomatic relations"

1. Grow worse
   "Conditions in the slum worsened"
   - decline
    
2. Make worse
   - aggravate, exacerbate, exasperate

See also: worse, worsening

Type of: alter, change, change state, modify, turn

Antonym: better