Unrealistic means not matching what can actually happen in the real world. When someone has unrealistic expectations about making the basketball team, they might imagine becoming the star player without practicing their free throws or working on their dribbling. When a plan is unrealistic, it ignores important facts about time, money, effort, or ability.

The word often points to a gap between imagination and reality. A movie might show unrealistic fight scenes where the hero never gets tired or hurt. A student's schedule might be unrealistic if it includes three hours of homework, two hours of piano practice, soccer practice, and bedtime by 8:30. Something unrealistic sounds good or feels possible in your mind but falls apart when you think about how things work in real life.

Being called unrealistic isn't the same as being called unimaginative. Imagination is wonderful and necessary. The problem comes when someone mistakes imagination for a solid plan.