A common and disgusting mispronunciacion and/or spelling of the word mischievous. Mischievous is pronounced "miss-CHI-vus" and there is no "ious" about it. Some people insist that
mischievious is an "alternate pronunciation," but only in the way that
irregardless is a synonym for regardless--that is to say, only for fucking retards.
Some argue that it is the evolution of language, but changes like this are driven by the illiterate and the ignorant, and it is careless to embrace them. And embarrassing.