Unscientific means not based on the careful methods and evidence that scientists use to understand the world. When something is unscientific, it ignores facts, skips proper testing, or draws conclusions without good evidence.

Science works through observation, experimentation, and testing ideas to see if they hold up. An unscientific approach might start with a conclusion someone wants to believe and then cherry-pick only the facts that support it, ignoring everything else. For example, claiming that a good luck charm definitely caused you to win a game is unscientific because you haven't tested whether you win more often with it than without it, and you're ignoring all the other factors like practice, skill, and chance.

Something can be unscientific in different ways. A claim might be unscientific because it can't be tested: if someone says they have an invisible, undetectable friend, science can't prove or disprove it. A method might be unscientific because it doesn't follow proper procedures: testing a medicine on just your cousin and concluding it works for everyone. Or reasoning might be unscientific because it jumps to conclusions without enough evidence: seeing two things happen together once and deciding one must have caused the other.

The word isn't always an insult. Art, music, friendship, and many valuable parts of life aren't scientific questions, and that's perfectly fine. But when someone claims something is scientifically true while using unscientific methods, that's when the word becomes a meaningful criticism.