Freezing point depression refers to the process where the addition of a solute to a solvent decreases the freezing point of the solvent. It is a colligative property, meaning it depends on the number of solute particles in a solution, not the identity of the solute. In toxicology, this principle can help explain the behavior of toxins in solutions, such as how they might remain in a liquid state at lower temperatures, potentially influencing their bioavailability and toxicity.