The term anodyne derives from Greek anōdynos (ἀνώδυνος), from an- (αν-, "without") and odynē (ὀδύνη, "pain").
[1] Some definitions restrict the term to topical medications, including herbal simples such as onion, lily, root of mallows, leaves of violet, and elderberry.
[4] In the 19th century, the primary anodynes were opium, henbane, hemlock, tobacco, nightshade (stramonium), and chloroform.
[1] Certain compound medicines were also called by this name, such as anodyne balsam, made of castile soap, camphor, saffron, and spirit of wine, and digested in a sand heat.
In literary usage, the word has escaped its strictly medical meaning to convey anything "soothing or relaxing" (since the 18th century) or even anything "non-contentious", "blandly agreeable", or unlikely to cause offence or debate.