However, you can use other adjectives to convey a similar meaning:
Comparative:
* More vast: This suggests a larger scale than something already vast.
* Wider: Emphasizes a greater breadth or extent.
* Greater: More general, implying a larger size or quantity.
* Larger: A direct comparison of size.
Superlative:
* Vastest: The ultimate in size or scope.
* Widest: Emphasizes the greatest breadth or extent.
* Greatest: The most significant or most extensive.
* Largest: The most significant in terms of size.
* Colossal: Extremely large and impressive.
The best choice depends on the specific context and the nuance you want to convey.