bombast

Concise Oxford English Dictionary © 2008 Oxford University Press:
bombast /ˈbɒmbast/

▶noun high-sounding language with little meaning.

– derivatives
bombastic /bɒmˈbastɪk/ adjective,
bombastically adverb.

– origin C16 (denoting cotton wool used as padding, later used figuratively): from OFr. bombace, from med. L. bombax, bombac-, alt. of bombyx ‘silkworm’.