The crossword solution for the term DOWNHILL SLOPE is RUN, which is a three-letter word. RUN is an activity that involves moving forward quickly by taking quick steps on alternate feet. It is a form of aerobic exercise that can be done in any environment and is often used as a form of exercise or for recreational purposes. RUN is also used to describe a situation that is getting worse or deteriorating quickly. In the context of DOWNHILL SLOPE, RUN is used to describe the situation of something getting worse or deteriorating quickly.