MOUTH SETTING' The crossword solution for the term 'MOUTH SETTING' is DELTA, which is a five-letter word. DELTA is a Greek letter that is often used to represent change in mathematics and science. In music, it is used to indicate a change in pitch or tone. In geography, DELTA is used to refer to a triangular area of land formed by the deposition of sediment at the mouth of a river. In dentistry, DELTA is used to refer to the setting of the mouth, which is the position of the lips, teeth, and jaw when speaking or smiling.