Source : Webster's Revised Unabridged Dictionary (1913)

Van't Hoff's law \Van't Hoff's law\ [After J.H. van't Hoff,
   Dutch physical chemist.] (Phys. Chem.)
   The generalization that: when a system is in equilibrium, of
   the two opposed interactions the endothermic is promoted by
   raising the temperature, the exothermic by lowering it.