The term 'Use a Witching Rod' refers to the practice of dowsing, which is a technique used to locate underground water, minerals, or other objects without the use of scientific instruments. Dowsing is also known as divining, doodlebugging, or witching, and is typically done with a forked stick, rod, or pendulum. The crossword solution for this term is 'DOWSE, ' which is a verb meaning to search for something by using a dowsing rod.