The term 'RANK UNDER A MARQUIS' can be solved by the crossword solution 'EARL', which is a four-letter word. An EARL is a British nobleman ranking below a marquis and above a viscount. Earls are usually members of the peerage, and are entitled to the style of 'The Right Honourable'. Earls have been around since the Norman Conquest of 1066, and were originally the highest rank of nobility in England.