viscosity

n. thickness, stickiness

Viscosity is a measure of the  resistance of a fluid to deform under either shear stress or extensional stress. It is commonly perceived as "thickness", or resistance to flow. Viscosity describes a fluid's internal resistance to flow and may be thought of as a measure of fluid friction. Thus, water is "thin", having a lower viscosity, while vegetable oil is "thick" having a higher viscosity. All real fluids (except superfluids) have some resistance to stress, but a fluid which has no resistance to shear stress is known as an ideal fluid or inviscid fluid. The study of viscosity is known as rheology.
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Viscosity /vis·cos·i·ty/ resistance to flow; a physical property of a substance that is dependent on the friction of its component molecules as they [more]Viscosity - Community and Resources

Noun
1. resistance of a liquid to sheer forces (and hence to flow)
(synonym) viscousness
(hypernym) consistency, consistence, body
(hyponym) stickiness

(n.)
The quality or state of being viscous.
  

(n.)
A quality analogous to that of a viscous fluid, supposed to be caused by internal friction, especially in the case of gases.