The term 'IT CAN CURL YOUR HAIR' is a crossword solution for the word PERM, which is a four-letter word. A perm is a chemical hair treatment that is used to permanently curl or straighten hair. It involves wrapping sections of hair around rods and then applying a chemical solution to the hair. The chemical solution breaks down the hair's natural bonds and reforms them into a new shape. After the chemical solution is rinsed out, the hair is set in its new shape.