perjury (n.)

late 14c., perjurie, in law, "the act of swearing to a statement known to be false, willful utterance of false testimony under oath," via Anglo-French perjurie (late 13c.) and Old French parjure "perjury, false witness," both from Latin periurium "a false oath," from periurare "swear falsely," from per "away, entirely" (see per) + iurare "to swear" (see jury (n.)). Related: Perjurious.