bombast

Short definition from Wiktionary

Noun

1. 1
   Cotton, or cotton wool.
2. 2
   Cotton, or any soft, fibrous material, used as stuffing for garments; stuffing, padding.
3. 3
   High-sounding words; language above the dignity of the occasion; a pompous or ostentatious manner of writing or speaking.

Verb

1. 1
   To swell or fill out; to inflate, to pad.
2. 2
   To use high-sounding words; to speak or write in a pompous or ostentatious manner.

Adjective

1. 1
   Big without meaning, or high-sounding; bombastic, inflated; magniloquent.