Real Mouthful is an idiom that means something is very difficult to say or understand. The crossword solutions for this term are CUD and WAD. CUD stands for a portion of food that is chewed again and again, while WAD is a small mass or lump of something, such as paper or cloth. Together, these two words form the phrase 'real mouthful, ' which is used to describe something that is hard to say or comprehend.