The crossword solution for the term 'WATCH __ STEP!' is 'YOUR', which is a four-letter word. This phrase is commonly used as a warning to be careful and to pay attention to where one is going. It is often used when someone is walking on a slippery or uneven surface, or when there is a risk of tripping or falling. The phrase is also used figuratively to remind someone to be mindful of their actions and words.