n. [ Of uncertain origin: cf. Dan. balder noise, clatter, and E. dash; hence, perhaps, unmeaning noise, then hodgepodge, mixture; or W. baldorduss a prattling, baldordd, baldorddi, to prattle. ] 1. A worthless mixture, especially of liquors. [ 1913 Webster ]

Indeed beer, by a mixture of wine, hath lost both name and nature, and is called balderdash. Taylor (Drink and Welcome). [ 1913 Webster ]

2. Senseless jargon; ribaldry; nonsense; trash. [ 1913 Webster ]

v. t. To mix or adulterate, as liquors. [ 1913 Webster ]

The wine merchants of Nice brew and balderdash, and even
mix it with pigeon's dung and quicklime. Smollett. [ 1913 Webster ]