The word "bumpoff" is often used as a slang term for murder or assassination. This term is colloquial and not suitable for formal communication. If you are looking for synonyms for "bumpoff", you may consider using phrases like "kill", "slay", "eliminate", "take out", "do away with", "dispatch", "execute", "assassinate", "liquidate", "exterminate", "put to death", "murder", "off", "rub out", "terminate", "wipe out", "finish off", "annihilate", or "eradicate". Each of these phrases carries a slightly different connotation and may be more suited to your specific situation.