Someone who thinks he is smart but is actually very stupid. A "know-it-none" as opposed to a "know-it-all". In particular, people who assume their success in one area entitles them to respect in another. (etymology: a portmanteau of the words "asinine" and the name of the bona fide genius "Albert Einstein" - coined by former Jeopardy! writer Ryan Hopak.)
"Glenn Beck spews so much bullshit he's the ultimate asininestein.", "The character Cliff Clavin on the sitcom Cheers was an asininestein."
"Adam insist on talking on speaker phone to his clients, so that the whole office can hear the conversation from his cubicle. This asininery has got to stop or I will have to strangle him with the cord from the handset he is not using!" -asininery.blogspot.com