Something that’s sparse is thin, not dense. If you’re looking for the perfect place to build a tree house, a sparse forest is probably not your best bet.
From the Latin sparsus, meaning “scattered,” we get the adjective sparse, which means “few and scattered.” Thinning hair is sparse, as is the population of an endangered species. Or a small and scattered crowd for an unpopular band. Synonyms include dispersed, infrequent, and scanty. Antonyms, on the other hand, include full, lush, and plentiful.