english
1
general::
Phrase(s): bump someone off [and] knock someone off Sl. to kill someone. • They tried to bump her off, but she was too clever and got away. • The crooks threatened to bump off the witness to the crime.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Kill, murder, as in The convict bragged about bumping off his partner, or The first fighter plane bumped off three enemy aircraft. This term was at first principally criminal slang and somewhat later military jargon. [Slang; c. 1900]
American Heritage Idioms