The term 'not very clear' can be summarized by two crossword solutions: 'DENSE' and 'NEBULOUS'. DENSE is a 5-letter word meaning 'thick, crowded, or compact'. NEBULOUS is an 8-letter word meaning 'vague, indistinct, or hazy'. Both words describe something that is not very clear, but in different ways. DENSE implies that there is too much information to make sense of, while NEBULOUS implies that the information is too unclear or hazy to understand.