1. A very boastful and talkative person; a braggart
2. A self-important egomaniac who likes to toot his own horn, like those assholes who put bumper stickers on their cars that say "PROUD PARENTS OF AN HONOR STUDENT AT (blah blah blah) HIGH SCHOOL"
"Did you catch the State of the Union speech last night? What a fucking blowhard!"
When a blogger gets all high and mighty and posts something that has them come off as tough and/or cool. Being bloghard usually consists of bashing other peoples blogs, bashing celebrities or musicians, or bashing common opinions without any real reason all from the comfort of their own living room.
"Hey did you guys hear that Brittany Murphy passed away?"