The answer to the crossword puzzle is ACU, which stands for Acupressure or Acupuncture. Acupressure is a form of alternative medicine that involves applying pressure to certain points on the body to relieve pain and tension. Acupuncture is a form of traditional Chinese medicine that involves inserting thin needles into the skin at specific points to stimulate the body's natural healing process. Both acupressure and acupuncture are used to treat a variety of ailments, including headaches, muscle pain, and stress.