Misbegotten describes something that was poorly conceived or badly planned from the very start. When a project is misbegotten, it means the original idea behind it was flawed or misguided. A misbegotten plan to raise money for your class trip by selling ice cream in January might fail because the basic concept didn't account for the winter weather.

The word carries a sense that something went wrong right at the beginning, at the moment of creation or planning. A misbegotten scheme is doomed not because of bad luck or poor execution, but because the fundamental idea never made sense. When historians call a war misbegotten, they mean it was a mistake to start it in the first place.

You might hear someone call an unsuccessful business venture a misbegotten enterprise, or describe a confusing art project as misbegotten. The word suggests that if someone had thought more carefully at the start, they would have realized the idea wouldn't work. It's the difference between a good plan that failed and a plan that was questionable from the moment someone first thought of it.