Mastodonic is one of those words that aren't used often in our day-to-day conversations, but it's useful to have synonyms to understand the concept it conveys. A few synonyms for mastodonic include gigantic, massive, colossal, mammoth, and enormous. These words are similar in meaning to mastodonic because they all describe something that is incredibly large. They are often used to describe large objects, structures, or animals, so we can use these words interchangeably with mastodonic in various contexts. Knowing these synonyms helps expand our vocabulary and allows us to better describe things we encounter that leave us in awe at their sheer size.