Bumping off is an idiomatic phrase that generally implies the act of killing someone or something. There are a few different synonyms that can be used for this phrase, depending on the context in which it is used. For example, "eliminating" is a commonly used synonym that may suggest a more deliberate and calculated approach to getting rid of someone or something. "Murdering" is a more blunt synonym that can be used in situations where the act of killing is particularly violent or brutal. Other potential synonyms for bumping off might include "assassinating," "dispatching," or "disposing of," each of which can convey slightly different shades of meaning depending on the context in which they are used.