1) French word used in English 2) Give false testimony 3) Swear falsely 1) Lie 
• (v. t.) To cause to violate an oath or a vow; to cause to make oath knowingly to what is untrue; to make guilty of perjury; to forswear; to corrupt; -- often used reflexively; as, he perjured himself. • (n.) A perjured person. • (v. t.) To make a false oath to; to deceive by oaths and protestations.
Per'jure noun [ Latin perjurus : confer Old French parjur , French parjure .] A perjured person. [ Obsolete] Shak. Per'jure transitive verb [ imperfect & past participle Perjured ; present participle & verbal noun Perjuring .] [ French parjurer , Latin perjurare , perjerare ; per through, over + jurare to swear. S...
[v] - knowingly tell an untruth in a legal court and render oneself guilty of perjury
perjure 1. To knowingly tell an untruth in a legal court and render oneself guilty of perjury. 2. To make (oneself) guilty of perjury by deliberately testifying falsely under oath.