What is pertaining to, or derived from, the dynamical action of water of a liquid; of or pertaining to water power. Hydrodynamic friction, friction produced by the viscosity of a liquid in motion called?

hydrodynamic — Pertaining to, or derived from, the dynamical action of water of a liquid; of or pertaining to water power. Hydrodynamic friction, friction produced by the viscosity of a liquid in motion. (Webster's 1913.)

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