v.1. To depart from some place, especially in order to begin a new stage of a journey: We left Paris behind and went on to Warsaw.
2. To abandon, neglect, or forego someone or something: I can't believe you would leave behind your whole family. We boarded the plane to Tahiti and left all our troubles behind. The teacher was afraid that the younger students were getting left behind.
3. To have someone or something remaining after one's death: When she died, she left behind two young children. Many of the soldiers who died in the war left families behind. The actor left behind a legacy when he died.
4. To depart or disappear, leaving something as a result: When the glacier receded, it left behind many small lakes.
5. To surpass someone or something: This new product will leave the competition behind.