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.Movement of liquids›[I or T]If a container or a place overflows, whatever is inside it starts coming out because it is too full: Oh no, the bath is overflowing all over the floor.The bin was overflowing with rubbish.Movement of liquidsC2[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: The bar was so full that people were overflowing into/onto the street.The train was (full to) overflowing (= so full that there was not space for any more passengers).His room is overflowing with books.Too much and unnecessaryto overflowing›so that water or another substance is almost coming over the top: Someone has filled the bath (full) to overflowing.Full