Which term refers to a substance that readily mixes with water?

The term that refers to a substance that readily mixes with water is "miscible." When two substances are miscible, they can be mixed together in any proportion without separating. This term is often used in chemistry to describe liquids that can dissolve in each other, such as alcohol in water. Miscibility indicates a complete blending or integration of the substances at a molecular level, leading to a homogenous solution.

In contrast, "soluble" generally applies to solid substances dissolving in a liquid, which is a subset of the broader concept of miscibility. Therefore, while miscible pertains specifically to liquids mixing well together, soluble pertains more to the ability of solids to dissolve in liquids.

The other terms do not accurately convey the idea of substances mixing well with water. "Insoluble" refers to substances that do not dissolve in a solvent, while "incompressible" refers to the property of materials that cannot be compacted or reduced in volume under pressure. These definitions highlight the specific nature of miscibility in the context of liquid interactions with water.