or·na·men·tal I. \|ȯ(r)nə|mentəl\adjective : having decorative quality or value < encourages the useful rather than the ornamental public virtues — Ellen Glasgow > • or·na·men·tal·i·ty\ˌ ̷ ̷ ̷ ̷_mən.ˈtaləd.ē, -ˌmen.-, -ləd.ē, -i\noun-es • or·na·men·tal·ly\| ̷ ̷ ̷ ̷|mentəlē, -əli\adverb • or·na·men·tal·ness\ˌ ̷ ̷ ̷ ̷ˈmentəlnə̇s\noun-es II. noun (-s) : a decorative object; especially: a plant cultivated for its beauty rather than for use