出典:Wiktionary
1960s, US military intelligence and CIA, used publicly in 1969, in news coverage of Green Beret Case, further popularized in 1979 movie Apocalypse Now.[1] Play on the term “terminate with prejudice” when an employee’s employment is terminated,[2] meaning “will not rehire employee to same position in future” (i.e., prejudiced against rehiring), hence “terminate definitively, i.e., kill”.
terminate with extreme prejudice (三人称単数 現在形 terminates with extreme prejudice, 現在分詞 terminating with extreme prejudice, 過去形および過去分詞形 terminated with extreme prejudice)