silver tongued devil. Silver tongue is an expression used to describe a person who has a clever way with words. Add some clever sarcasm, or sleazy lies to this person's attitude, and there you have your silver tongued devil. I honestly can't believe I'm making a bible reference, but this is what Google gave up for silver tongued devil: When Satan with his silver-tongue approached Eve, using the serpent as a mouthpiece, note that the very first thing he did was to question the veracity of God’s spoken word.