The term 'swell outward' can be summarized by the crossword solution 'BULGE, ' which is a five-letter word. Bulging is a physical phenomenon that occurs when an object or surface expands outward due to pressure from within. It is often seen in balloons, waterbeds, and other objects that are filled with air or liquid. Bulging can also occur in the body, such as when muscles become enlarged due to exercise.