Русско-англо-русский юридический словарь

Perjury is the intentional act of swearing a false oath or falsifying an affirmation to tell the truth, whether spoken or in writing, concerning matters material to an official proceeding. (Wikipedia)

perjurer. n. a person who intentionally lies while under an oath administered by a notary public, court clerk or other official, and thus commits the crime of perjury. (Free Dictionary)

Knowingly false testimony may expose a witness to a charge of perjury or obstruction of justice. (Grand Jury Practice by Howard W. Goldstein, Steven M. Witzel)