term:

Perjury

perjury n

pl: -ries
[Anglo-French perjurie parjurie, from Latin perjurium, from perjurus deliberately giving false testimony, from per- detrimental to + jur- jus law]
: the act or crime of knowingly making a false statement (as about a material matter) while under oath or bound by an affirmation or other officially prescribed declaration that what one says, writes, or claims is true compare false swearing

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.