Messily means doing something in a way that creates disorder, confusion, or untidiness. When you eat spaghetti messily, sauce ends up on your shirt, face, and maybe even the table. When you pack your backpack messily, papers get crumpled, pencils fall out, and you can never find what you need.

The word describes the manner or style of an action rather than its final result. A toddler learning to feed herself eats messily because she's still developing coordination. An artist might work messily, with paint splattered everywhere, but create something beautiful. A scientist's first attempts at an experiment can proceed messily before the process gets refined.

Sometimes messily describes emotional situations too. When a friendship ends messily, there might be hurt feelings, arguments, and confusion instead of a calm conversation. Complex problems rarely get solved neatly: they get worked through messily, with setbacks and mistakes along the way.

The opposite would be neatly, carefully, or tidily. Notice that messily isn't always bad. Learning new skills almost always happens messily at first.