twaybladePronunciation: /ˈtweɪbleɪd/Definition of twayblade noun an orchid with a slender spike of greenish or brownish flowers and a single pair of broad leaves near the base. Genus Listera, family Orchidaceae: several species, including the Eurasian common twayblade (L. ovata) Origin: late 16th century: from tway (variant of twain) + blade, translating Latin bifoliumtwayblade in other Oxford dictionaries Definition of twayblade in the US English dictionary