Overflow/ˌəʊvərˈfləʊ/ Definition 1 of 4Pro Tip 1/3Overflowing Container Used when something physically can't fit within its space and spills out. Her jewelry box overflowed with trinkets. Pro Tip 2/3Emotional Intensity Indicates an abundance of strong feelings that cannot be contained. His heart overflowed with happiness. Pro Tip 3/3Unexpected Abundance Suggests a situation where there is more of something than was planned or desired. The party had an overflow of guests.