What is the term for a liquid that is thick and sticky?

The term that describes a liquid that is thick and sticky is "viscous." Viscosity refers to a liquid's resistance to flow; higher viscosity means that a liquid is thicker and flows less easily, making it sticky or gooey in nature. Common examples of viscous substances include honey, syrup, and molasses, which exhibit substantial thickness compared to water.

In contrast, the other terms do not convey the same meaning. Fluid includes a broad range of liquids and does not specifically denote thickness or stickiness. Aqueous refers to a solution in which water is the solvent, typically implying a runny consistency rather than thickness. Oily refers to substances that are oil-based, which can be viscous but is not inherently a synonym for thick and sticky, as some oils can be quite thin. Therefore, viscous is the term that accurately captures the quality of being thick and sticky.