bombast

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Grandiloquent, pompous speech or writing.
• noun Grandiose or overpowering expression, as in music or painting.

from The Century Dictionary.

• To pad out; stuff, as a doublet with cotton; hence, to inflate; swell out with high-sounding or bombastic language.
• To beat; baste.
• noun Cotton; the cotton-plant.
• noun Cotton or other stuff of soft, loose texture, used to stuff garments; padding.
• noun Figuratively, high-sounding words; inflated or extravagant language; fustian; speech too big and high-sounding for the occasion.
• noun Synonyms Bombast, Fustian, Bathos, Turgidness, Tumidness, Rant. “Bombast was originally applied to a stuff of soft, loose texture, used to swell the garment. Fustian was also a kind of cloth of stiff, expansive character. These terms are applied to a high, swelling style of writing, full of extravagant sentiments and expressions. Bathos is a word which has the same application, meaning generally the mock-heroic—that ‘depth’ into which one falls who overleaps the sublime: the step which one makes in passing from the sublime to the ridiculous.” (De Mille, Elements of Rhetoric, p. 225.) Bombast is rather stronger than fustian. Turgidness and tumidness are words drawn from the swelling of the body, and express mere inflation of style without reference to sentiment. Rant is extravagant or violent language, proceeding from enthusiasm or fanaticism, generally in support of extreme opinions or against those holding opinions of a milder or different sort.
• High-sounding; inflated; big without meaning.

from the GNU version of the Collaborative International Dictionary of English.

• adjective High-sounding; inflated; big without meaning; magniloquent; bombastic.
• noun obsolete Originally, cotton, or cotton wool.
• noun obsolete Cotton, or any soft, fibrous material, used as stuffing for garments; stuffing; padding.
• noun Fig.: High-sounding words; an inflated style; language above the dignity of the occasion; fustian.
• transitive verb obsolete To swell or fill out; to pad; to inflate.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Originally, cotton, or cotton wool.
• noun Cotton, or any soft, fibrous material, used as stuffing for garments; stuffing; padding.
• noun figuratively High-sounding words; an inflated style; language above the dignity of the occasion; fustian.
• verb To swell or fill out; to pad; to inflate.
• adjective High-sounding; inflated; big without meaning; magniloquent; bombastic.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun pompous or pretentious talk or writing