Mid 19th century; earliest use found in The Edinburgh Review. From ancient Greek διδαχή teaching, in Hellenistic Greek also specifically with reference to Christian teaching and as the first word of the title of the treatise Διδαχὴ κυρίου διὰ τῶν δώδεκα ἀποστόλων τοῖς ἔθνεσιν, lit. ‘teaching of the Lord through the twelve apostles to the nations’ from διδάσκειν to teach, probably influenced in form by perfect forms such as δεδίδαχθαι (passive infinitive), δεδίδαχα (1st person singular).