Disadvantageous means putting you in a worse position or causing you harm compared to what you need or want. If something is disadvantageous, it works against you rather than helping you succeed.

Making a disadvantageous trade means you give up something valuable and get back something worth less, like trading your favorite video game for one you've already played and didn't enjoy. A disadvantageous position in chess means your pieces are poorly placed and your opponent has the upper hand. If you agree to disadvantageous terms in a deal, you've accepted conditions that hurt your chances of getting what you want.

Where an advantage helps you, a disadvantage holds you back. Something disadvantageous creates disadvantages for you. A basketball player forced to shoot with their weaker hand is in a disadvantageous situation. A runner starting a race ten meters behind the starting line faces disadvantageous conditions.

You might hear people say it would be disadvantageous to skip studying before a big test, or that picking a fight with someone twice your size puts you in a disadvantageous position. The word warns you when circumstances or choices might work against your success.