SLOP OVER is a term used to describe the act of spilling or overflowing something. It is often used in reference to liquids, such as water or other beverages, but can also be used to describe the spilling of other materials, such as grains or powders. The term is derived from the verb 'SLOP, ' which means to SPILL or overflow. The term 'OVER' is added to indicate that the spilling has gone beyond the intended boundaries.