Matures' Aging cheese is a process that can take months or even years, depending on the type of cheese. The term 'mellows, as cheese' refers to the process of aging cheese, which is also known as ripening. During this process, the cheese develops its flavor and texture, and it becomes softer and more flavorful. The crossword solution for the term 'mellows, as cheese' is 'AGES, ' which is a four-letter word that accurately describes the process of aging cheese.