coagulate

This term describes a specific physical transformation where a liquid becomes a gel or a solid. It is most frequently encountered in medical or biological contexts, such as the clotting of blood or the curdling of milk, carrying a clinical and precise tone. While it can be used transitively to describe an external agent causing the change, the intransitive use focuses on the natural process of the substance itself thickening. It differs from simple drying or freezing as it implies a chemical or structural change in the fluid's composition.