The term 'EXTREMELY MAD' can be described by two crossword solutions: IRATE (5 letters) and SORE (4 letters). IRATE is an adjective that means 'very ANGRY or furious'. It is derived from the Latin word 'iratus', which means 'ANGRY'. SORE is an adjective that means 'feeling or showing pain, distress, or resentment'. It is derived from the Old English word 'sar', which means 'PAINFUL'. Therefore, the term 'EXTREMELY MAD' can be accurately described as 'very ANGRY or furious' and 'feeling or showing pain, distress, or resentment'.