Soliloquy

In the theater, a speech by a character alone on stage, who thinks aloud and shows the audience what he does not say to the others.

In Macbeth

Come, you spirits / That tend on mortal thoughts, unsex me here, / And fill me from the crown to the toe top-full / Of direst cruelty. [...] Come to my woman's breasts / And take my milk for gall, you murd'ring ministers

The invocation is spoken alone, with no one else on stage, so the audience hears without a filter what she wants: to be emptied of pity and filled with "the most dreadful cruelty."

Act I: The Prophecy and the Temptation, Lady Macbeth

Is this a dagger which I see before me, / The handle toward my hand? [...] I see thee still, / And on thy blade and dudgeon gouts of blood, / Which was not so before.

Act II: The Murder of Duncan, Macbeth

If 't be so, / For Banquo's issue have I filed my mind; / For them the gracious Duncan have I murdered, / Put rancors in the vessel of my peace / Only for them [...]

Act III: The King Ruled by Fear, Macbeth