1580s, "obscene quality," from French obscénité, from Latin obscenitatem (nominative obscenitas) "inauspiciousness, filthiness," from obscenus "offensive" (see obscene). Meaning "a foul or loathsome act" is 1610s. Sense of "an obscene utterance or word" is attested by 1690. Related: Obscenities.[obscenity etymology, obscenity origin, 英语词源]