* Dense: This is a general antonym for sparse, meaning "thickly packed or crowded."
* Abundant: This implies a large quantity or amount, the opposite of scarcity.
* Plentiful: Similar to abundant, this refers to something that is easily available in large quantities.
* Copious: This describes something that is large in amount or number.
* Profuse: This suggests an overflowing abundance.
The best antonym will depend on the specific meaning of "sparse" in your context.