perjury vs lying under oath

perjury and lying under oath both are nouns.

Word	Noun	Adjective	Verb	Adverb
perjury	Yes	No	No	No
lying under oath	Yes	No	No	No

As nouns, perjury and lying under oath are synonyms defined as:

perjury and lying under oath: criminal offense of making false statements under oath

Other synonyms of perjury include bearing false witness.

perjury (noun)	lying under oath (noun)
criminal offense of making false statements under oath	criminal offense of making false statements under oath