viscous

This term describes a physical resistance to flow. It evokes a sense of heaviness and sluggishness, where a liquid clings to surfaces rather than splashing or running freely. It is most commonly used in scientific, industrial, or culinary contexts to describe the internal friction of a fluid. While "sticky" refers to the adhesive quality of a substance clinging to another object, "viscous" refers to the internal thickness of the fluid itself. A substance can be viscous without being sticky, like heavy motor oil, whereas honey is both viscous and sticky.