De-knot is a term used to describe the process of untying knots. It is often used in the context of untangling ropes, strings, or other materials that have become knotted. The term can also be used to describe the process of removing tangles from hair or fabric. In the crossword puzzle, the solution for the term de-knot was 'UNTIE, ' which is an appropriate action to take when trying to de-knot something.