A Descriptive Word for Blow Hards

I've been seeing this word all over the blogosphere, and while I got the gist, I was curious about its official definition.
From Merriam Webster Online:

Main Entry: blo·vi·ate
Pronunciation: 'blO-vE-"At
Function: intransitive verb
Inflected Form(s): -at·ed; -at·ing
Etymology: perhaps irregular from 1blow
: to speak or write verbosely and windily
- blo·vi·a·tion /"blO-vE-'A-sh&n/ noun