A person who at first appears to be normal but who gradually, over time, reveals himself or herself to be nothing more than an idiot. Derived from a merging of the words "insidious" and "idiot".
"The guy sitting beside me on the plane seemed like a cool guy, but the more he kept talking, I came to realize that he was nothing more than an insidiot"
by fredogonefishin April 02, 2014
1 more definition
A person who knowingly acts in a devious and treacherous way to sabotage another person's well-being while simultaneously putting their own well being at risk.
The insidiot did everything in her power to ruin her ex-husband's business with no regard for the ill-effects it would have on her financial health.
by KMUSE July 02, 2013