'Down the Hatches!' is an idiom that is used to express a sense of urgency and preparation for something. It is often used when someone is about to embark on a difficult task or situation. The term 'BATTEN' is a 6 letter word that is related to this phrase. It means to secure or fasten something down, usually referring to hatches on a boat. Therefore, the crossword solution of 'BATTEN' for the term 'Down the Hatches!' is appropriate as it refers to the act of securing the hatches in preparation for a difficult situation.