slan·der·ous \-d(ə)rəs\adjective Etymology: Middle English sclaundrous, from sclaundre slander + -ous 1.obsolete: being a source or occasion of scandal or disgrace 2.: containing or constituting slander : calumnious < a slanderous utterance > 3.: given to or uttering slander < a slanderous tongue > • slan·der·ous·lyadverb • slan·der·ous·nessnoun-es