Incompletely means in a way that is not finished, not whole, or missing important parts. When you do something incompletely, you've left out steps or pieces that should be there.

If you read the instructions for building a model airplane incompletely, you might skip crucial details and end up with loose parts that don't fit right. When a student completes their homework incompletely, they've answered some questions but left others blank, or they've given partial answers that don't fully address what was asked.

The word shows up often in science and research. A fossil might be incompletely preserved, with some bones missing. A medical study done incompletely might draw conclusions without gathering enough data. Scientists are careful to note when something is incompletely understood because they know missing pieces can change the whole picture.

The opposite is completely, meaning fully or entirely. If you completely clean your room, every corner is tidy. If you clean it incompletely, you've stuffed things under the bed or left clothes on the floor. The difference matters: work done incompletely often needs to be redone, while work done completely stands on its own.