(a.), literally, “something made obscure, hidden”.
1. In the sense of word puzzle, riddle [see lug̲h̲z ].
2. In the sense of secret writing, code. Codes were regularly used in classical Antiquity. Thus the skytalē of the Spartans, mentioned by Plutarch, in which a message was written on a parchment or leather ribbon which was wrapped round a tapered wooden baton for purposes of writing and then could only be read by a recipient possessing a baton of the same shape and size, is an early example of a typical transposition cipher. …