The term 'THIN DOWN' can be summarized by the crossword solution 'DILUTE, ' which is a 6-letter word. DILUTE means to make something weaker or less concentrated by adding a liquid or other substance. This term is often used in cooking, where it is necessary to add water or other liquids to a mixture in order to reduce its thickness or consistency. It can also be used to describe the process of reducing the strength of a solution or mixture by adding more of the same substance.