In Macbeth, a "filthy witness" refers to someone who has seen or knows about a crime or wrongdoing. This term reflects the idea that the witness's testimony or knowledge is tainted or corrupt due to the nature of the events they have witnessed.
The "filthy witness" which Lady Macbeth talks about washing from Macbeth's hands is, of course, Duncan's blood. "Filthy" because it is dirty and smells unpleasant. (Have you ever been covered in blood?) "Witness" because its presence on his hands marks him as the murderer--it testifies against him.
"Go get some water, and wash this filthy witness from your hand." In other words, she is trying to distract him.
It means evidence in the form of blood or gore.
Lady Macbeth speaks these lines in response to Macbeth's guilt over murdering King Duncan. She urges him to wash away the evidence of the murder from his hands and tries to calm his anxious thoughts by dismissing them as irrational. Lady Macbeth brings the daggers used in the murder as evidence of Macbeth's involvement in the deed.
foul filthy
"Fair is foul and foul is fair. Hover in the fog and filthy air."
The meaning of this remark is that there is no faith in a witness who tends to lie or whose reputation is in such a damaged state that his assurances cannot be trusted. It is worth noting the following - otherwise the truth would not depend on the source from which it originates. In other words, this can definitely be considered a special case of false argumentation, such as: “how can you be a supporter of vegetarianism if Hitler was a vegetarian” or “you are from Kiev / from Moscow, so your statements have such meaning” / “that’s yourself- then you smoke/don’t smoke, that’s why you say so and are so determined.”
For a pitcher to throw unhitable pitches. For Example Clayton Kershaw has a filthy slider.
because Lady Macbeth talks about the murder, and the Lady in waiting has no witness for her speech
Filthy could mean unwashed, begrimed, polluted, slovenly, verminous, depraved, or indecent.
filthy
A witness is someone who was present at an occurrence.