Bombast - originally, cotton or any soft material used for padding to produce clothes in the fashion of the Sixteenth Century. It has come to mean a highflown unnatural style, rather inflated and insincere, pretentious, ranting, and using extravagant language. Also, it can denote extravagance at the expense of content.
The word is from the Greek bombux, meaning “silkworm” or “silk,” and the Latin bombyx, meaning “silkworm,” “something made of silk, any fine fiber, or cotton.” Both were used to form the Old French bombace, meaning “cotton.”
In Shakespeare’s Othello, Iago uses the word in complaining to Roderigo about Othello:
But he, as loving of his own pride and purposes,
Evades them with a bombast circumstance
Horribly stuff’d with epithets of war;
And, in conclusion,
Nonsuits my mediators.
Act I, scene i : lines 13 – 17