There are several synonyms for the phrase "leave over," all of which convey the idea of saving or reserving something for later. One common synonym is "set aside," which can be used in the context of saving food for another meal or money for a specific purpose. Another option is "reserve," which can refer to holding a seat or room for someone or setting aside resources for a particular project. "Hold back" is a similar phrase that can mean to save something for a later time or to refrain from giving or doing something immediately. Ultimately, the specific synonym used will depend on the context in which it is being used.