slanderous (adj.)

late 13c., sclaundre, "state of impaired reputation; disgrace or dishonor;" c. 1300, "a false tale or report spread maliciously; the fabrication and dissemination of false tales to discredit someone," from Anglo-French esclaundre, Old French esclandre "scandalous statement," alteration ("with interloping l" [Century Dictionary]) of escandle, escandre "scandal," from Latin scandalum "cause of offense, stumbling block, temptation" (see scandal).

It is attested from mid-14c. as "action or situation that brings shame or disgrace;" late 14c. as "a bad situation, evil action" and in reference to a person causing such a state of affairs.

The injury [slander] consists in falsely and maliciously charging another with the commission of some public offense criminal in itself, and indictable, and subjecting the party to an infamous punishment, or involving moral turpitude, or the breach of some public trust, or with any matter in relation to his particular trade or vocation, and which, if true, would render him unworthy of employment ; or, lastly, with any other matter or thing by which special injury is sustained. [James Kent, "Commentaries on American Law," 1844]

word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."