What term describes a substance that readily dissolves in a solvent?

The term that describes a substance that readily dissolves in a solvent is "soluble." When a substance is soluble, it means that it can mix with a solvent at the molecular level, forming a homogeneous solution. This characteristic allows the solute (the substance being dissolved) to disperse uniformly throughout the solvent, often resulting in a clear liquid.

In contrast, other terms provide different meanings: "insoluble" refers to substances that cannot dissolve in a given solvent, making it clear why it does not fit the description of readily dissolving. A "precipitate" is a solid formed from a solution during a chemical reaction, usually when two soluble substances produce an insoluble compound, and this does not relate to the ability to dissolve. Lastly, a "colloid" is a mixture where small particles are dispersed throughout a medium but do not settle out, which also does not pertain to the ability of a substance to dissolve completely. Thus, "soluble" is the correct terminology to describe a substance that dissolves readily in a solvent.