Powdery residue is a term used to describe the fine particles of matter that are left behind after something has been burned or disintegrated. The three crossword solutions for this term are ASH (3 letters), ASHES (5 letters), and DUST (4 letters). ASH is the solid remains of a fire, while ASHES are the powdery residue that is left behind after the fire has been extinguished. DUST is a fine powdery substance that is made up of tiny particles of matter.