The crossword solution for the term 'KEEP IN A BARREL' is AGE, which is a three-letter word. AGE is a verb meaning to store something over a period of time, usually in a barrel or other container. This is often done with food items such as wine, whiskey, and other alcoholic beverages, as well as certain types of cheese and other perishables. Ageing can also refer to the process of maturing or developing something over time, such as a person or an idea.