"Become full" is a phrase that refers to the process of something reaching its maximum capacity or being complete. There are many different synonyms that can effectively communicate the same idea, such as "fill up", "top off", "stuff", "load", or "saturate". These words can be used to describe a wide range of situations, from filling up a gas tank or a glass of water to overflowing, to completing a task or achieving a goal. Whatever the context, using these synonyms for "become full" can help to add variety and clarity to your writing or conversation.