Webster's Revised Unabridged Dictionary · 1913

Balderdash

Balderdash ({not transcribed}) , noun

[Of uncertain origin: compare Danish balder noise, clatter, and English dash; hence, perhaps, unmeaning noise, then hodgepodge, mixture; or Welsh baldorduss a prattling, baldordd, baldorddi, to prattle.]

1.
A worthless mixture, especially of liquors.
Indeed beer, by a mixture of wine, hath lost both name and nature, and is called balderdash. — Taylor (Drink and Welcome)
2.
Senseless jargon; ribaldry; nonsense; trash.

Balderdash ({not transcribed}) , transitive verb

To mix or adulterate, as liquors.
The wine merchants of Nice brew and balderdash, and even mix it with pigeon's dung and quicklime. — Smollett