As a Noun:
1. The act of deliberately not doing something or saying that you will not do it. English = refusal.
As a Verb or Adjective:
1. To deliberately intend not to do something or to say you will not do something. English = refuse.
1. Used alone as an interruption or comment on what someone is talking about meaning that you do not think it will happen at all (you strongly disagree); or used alone in answer or response to a request or command to do something to mean that you will definitely not do it or not obey. English = no way, definitely not, etc.
1. Used before or after a verb (action) sign in a sentence to mean the person doing the action does not intend to do it in the future or, if the actor is a thing, that someone feels that is certain not to happen in the future. English = will not, won't, wouldn't.