fornication vs criminal conversation

fornication and criminal conversation both are nouns.

Word	Noun	Adjective	Verb	Adverb
fornication	Yes	No	No	No
criminal conversation	Yes	No	No	No

As nouns, fornication and criminal conversation are synonyms defined as:

fornication and criminal conversation: extramarital sex that willfully and maliciously interferes with marriage relations

Other synonyms of fornication include adultery.

fornication (noun)	criminal conversation (noun)
voluntary sexual intercourse between persons not married to each other	extramarital sex that willfully and maliciously interferes with marriage relations
extramarital sex that willfully and maliciously interferes with marriage relations