It is in the denominator of the Reynolds number.
According to kinetic theory, this quantity equals the thermal conductivity times two-thirds times mass over Boltzmann's constant, which makes it scale with the square root of mass times temperature. The normal stress on a control volume includes a term equal to two-thirds this quantity, times the divergence of velocity. The Laplacian of velocity is multiplied by a tensor representing this quantity in the Navier-Stokes equations. A non-zero value for this quantity leads to the no-slip condition in boundary layers. This quantity is the slope of a graph plotting shear stress against strain rate; consequentially, it decreases at increasing shear stress for dilatant fluids. It is in the denominator of the Reynolds number. It's constant for Newtonian fluids. For 10 points, name this quantity measured in centipoise, which is roughly the fluid's resistance toward flowing.
According to kinetic theory, this quantity equals the thermal conductivity times two-thirds times mass over Boltzmann's constant, which makes it scale with the square root of mass times temperature.
viscosity [or kinematic viscosity; or dynamic viscosity]