'balderdash' appears in Early Modern English (early 17th century); its ultimate origin is uncertain. The word likely combines or alters earlier English elements such as 'bald' or dialectal terms plus 'dash', producing a term for a jumble or nonsense.

'balderdash' is recorded in 17th-century English with forms essentially the same as the modern word; earlier influences are unclear, and no single source word has been definitively identified.

Originally used for a 'jumble' or a 'concoction' (sometimes applied to mixed liquids or a mess), it soon came to be used chiefly for 'nonsense' and has retained that meaning into modern usage.