Heavily is an adverb that is often used to describe something that has a significant weight or mass on it. However, there are several synonyms for the word that can be used to add variety to your writing. Some synonyms for the word heavily may include: weightily, massively, ponderously, stupendously, enormously, excessively, burdensomely, significantly, substantially, and aboundingly. These alternative words allow for more descriptive language and help to paint a more vivid picture for the reader. When used correctly, synonyms can enhance the credibility of your writing and make it more interesting for your audience.