A heretical group listed by St John of Damascus (On Heresies, 8th cent.) but otherwise unknown, supposed to pray standing rather than kneeling. Usually in plural.
Mid 17th century; earliest use found in Alexander Ross (1591–1654), Church of England clergyman and writer on philosophy. From post-classical Latin Agonyclita from Byzantine Greek Ἀγονυκλίτης from ancient Greek ἀ- + γόνυ knee + -κλιτος from the stem of κλίνειν to bend + -τος, suffix forming verbal adjectives.