Take the tiller is a nautical term that refers to the act of taking control of the steering mechanism of a boat. It involves taking hold of the tiller, which is a lever or handle used to STEER the boat, and using it to direct the boat's course. The term is often used in sailing and other water-based activities. The crossword solution for this term is 'STEER', which is an appropriate word to describe the action of taking the tiller.