The viscosity of the liquid will be increasing.
The bond that holds the particles of liquid together is weak compared to solid.
The application of heat to a substance gradually causes a decrease in its viscosity because the molecules of the liquid substance get excited when the liquid is heated up.
When the temperature of the liquid is gradually decreased, the energy that causes the molecules to move will no longer be enough to overcome the forces that bind the molecules together causing the liquid to become thicker and increasing the viscosity of the liquid.
Therefore we can conclude that when the temperature of a liquid is gradually decreased, the viscosity of the liquid will be increasing.
