If
viscosity is a univalued function of the rate of shear, a decrease of the
viscosity with increasing rate of shear is called shear thinning, and an increase of the
viscosity shear thickening.
Source:
PAC, 1979, 51, 1213
(Manual of symbols and terminology for physicochemical quantities and units. Appendix II: Definitions, terminology and symbols in colloid and surface chemistry. Part 1.13. Selected definitions, terminology and symbols for rheological properties)
on page 1217
