inexplicable

Something inexplicable can't be explained. It doesn't make sense. You don't want to come to the beach on the most beautiful day of the year? That's inexplicable! Remember that “in” can mean “not” and explicable sounds like explainable, which helps you remember that inexplicable means “not explainable.” Used in a sentence, “The jury’s decision was inexplicable, as there is no way he was guilty!”