As a Noun: 1. A thing which is very bad indeed and more so than all the other things of its type you can compare it with. English = the worst. As a Verb or Adjective: 1. To be one of two things which you dislike more than the other thing. The one you dislike is very bad and more so than the other thing you can compare it with. English = (be) worse. 2. To be more ill than you were before; to be more sick. English = (be) worse, get worse, worsen. As Modifier: 1. Used before or after a verb to mean that the action is done by someone or something in a bad way and more so than another one you are thinking of and comparing it with. English = worse. 2. Used before or after a verb to mean that the action is done by someone or something in a very bad way indeed-more so than all others you can compare it with. English = worst.