Definition of "unriddle"

It will be found, when the Myſterie of iniquitie ſhall be unriddled, that, as they were their ſpawn the Anabaptiſts, the obſtructers of our Doctrinal Reformation, ſo, they are by their Miſſionaries ſent unto Corners and Hillie Countreys the obſtructers of our practical.

1702, [John Wilson], An Essay wherein National Love and Unity is Recommended, Its Opposits Exposed, Arguments for It Propounded, and Its Standard Expounded, and All Contenders Blamed. […], Edinburgh: Printed by the heirs and successors of Andrew Anderson, […], page 22

'I your Enemy, Sir!' ſays he, with much Amazement, and ſome Sternneſs in his Look. 'Nay, be not angry,' ſaid Benjamin, 'for I promiſe you I am not. You are perfectly innocent of having intended me any Wrong; for you was then an Infant; but I ſhall, I believe, unriddle all this the Moment I mention my Name. Did you never hear, Sir, of one Partridge, who had the honour of being reputed your Father, and the Misfortune of being ruined by that Honour?'

1749, Henry Fielding, “In which More of the Talents of Mr. Benjamin will Appear, as well as Who this Extraordinary Person was”, in The History of Tom Jones, a Foundling, volume III, London: A[ndrew] Millar, […], book VIII, page 186