Sparser is a word that refers to something that is less dense or less frequent in occurrence. Some useful synonyms for sparser include less abundant, scarcer, rarer, thinner, and more scattered. These words convey the idea of something being present in smaller quantities or being more widely spaced out. Other synonyms for sparser can include more intermittent, less frequent, more limited, or more isolated. Whatever synonym you choose, the idea is always the same - something that is not as plentiful as it once was or as expected. By using different synonyms, you can add more variety and color to your writing and express your ideas in a more nuanced manner.