The term 'REALLY CLEAN' can be described by three crossword solutions: SPOTLESS (8 letters), SCOUR (5 letters), and SCRUB (5 letters). SPOTLESS means to be completely clean, free of dirt or stains. SCOUR is an action that involves vigorous scrubbing or brushing in order to clean something. SCRUB is also an action, but it is more gentle than scouring and usually involves using a brush or sponge with soap or detergent. All three words describe the same concept of being really clean.