An accusation is the statement itself: you say, in words or in writing, that a person did something wrong. It may be a crime, a lie, a broken promise, or some smaller harm. People use it in court and in the news, and they also use it in ordinary fights (“That’s a serious accusation”). Though actually, an accusation is not proof. It is only the claim. You can make one and still be wrong, and other people will often ask you to back it up. In everyday talk, people sometimes stretch the word: any sharp complaint can get called an accusation, even when nobody is talking about the law.

指控；控告