Which word best describes something that is lavish or of great expense?

The term "sumptuous" is ideal for describing something that is lavish or of great expense. This word conveys a sense of richness, luxury, and extravagance. It suggests an abundance of taste and opulence, often associated with high quality and expensive materials or experiences. For instance, a sumptuous meal would imply dishes that are not only delicious but also beautifully presented and made with rich ingredients, thus appealing to both the senses and the idea of indulgence.

In contrast, the other words do not convey the same sense of luxury. "Spartan" suggests minimalism and a lack of indulgence, often associated with simplicity and even austerity. "Subdued" refers to something characterized by restraint or a lack of vibrancy, which is opposite to the lavish nature of sumptuousness. "Simple" indicates a lack of complexity or adornment, emphasizing straightforwardness rather than opulence. Thus, "sumptuous" stands out as the best choice to denote something that is lavish and expensive.