To flow or run over the top, brim, or banks: The river overflowed and flooded surrounding neighborhoods. 2. To be filled beyond capacity, as a container or waterway. 3. To have a boundless supply; be superabundant.

overflow verb (TOO FULL) C2 [ I or T ] When a liquid overflows, it flows over the edges of a container, etc. because there is too much of it: The milk overflowed when I poured it into the jug. Because of heavy rain, the river may overflow its banks. [ I or T ]

1 : to cover with or as if with water : inundate 2 : to flow over the brim or top of the river overflowed its banks 3 : to flow over bounds the creek overflows every spring

If a container or a place overflows, whatever is inside it starts coming out because it is too full: Oh no, the sink is overflowing all over the floor. The bin was overflowing with rubbish. C2 [ I ] When a place overflows, or people or things overflow from somewhere, some people or things have to come out because it cannot contain them all: