The term 'terribly bad' can be described by two crossword solutions: 'EVIL' (4 letters) and 'AWFUL' (5 letters). Both words are used to describe something that is of a very poor quality or has negative connotations. EVIL is often used to describe something that is morally wrong, while AWFUL is used to describe something that is unpleasant or distasteful. Together, these two words can be used to describe something that is extremely bad or of a very low quality.