Undecorated means plain, simple, or without ornaments or embellishments. An undecorated room has bare walls with no pictures, posters, or decorations hanging on them. An undecorated cake is just cake and frosting, without sprinkles, flowers, or fancy designs piped on top.

Sometimes being undecorated is a problem: an undecorated gym looks sad and empty on the night of the school dance. But sometimes simplicity works better. An undecorated essay focuses on strong ideas and clear writing instead of trying to sound fancy. An undecorated speech delivers its message directly without unnecessary flourishes.

The word can also refer to military honors. An undecorated soldier is one who hasn't received medals or awards, though this doesn't mean they haven't served honorably. A decorated soldier, by contrast, has earned medals recognizing specific acts of bravery or service.

Whether something should be decorated or left undecorated depends on the situation. A birthday party feels more festive with decorations, but a serious presentation might work better when it's kept simple and undecorated.