The term 'GET REALLY MAD' can be summarized by two crossword solutions: SEETHE (6 letters) and HITTHEROOF (10 letters). SEETHE is an informal expression used to describe someone who is very angry, while HITTHEROOF is a phrase that implies someone is so mad they are about to explode. Both of these expressions are used to describe someone who is extremely angry, and they are often used in informal contexts.