abgebrüht

Attested from the 16th century. Formally, ab (“off”) + gebrüht (“scalded, boiled”), based on the idea that things are hardened or “steeled” by boiling (e.g. eggs, compare hartgesotten, English hard-boiled). At the same time, perhaps originally, from vulgar Middle Low German brǖden (“to fuck”, also in the sense of “to afflict”), cognate and synonymous with early modern German bräuten, from Braut (“bride”); meaning that someone is the opposite of “innocent”.