Randomly means happening without any pattern, plan, or predictable order. When your teacher randomly calls on students, nobody knows who will be picked next: there's no list, no taking turns, just pure chance. When you shuffle a deck of cards, they end up in a random order where any card could appear anywhere.

Something done randomly has no hidden logic behind it. If you're randomly choosing teams for kickball, you might pull names from a hat rather than picking friends or the best players. Scientists use random selection in experiments to avoid bias: they might randomly assign patients to receive either a new medicine or a placebo to ensure fair results.

The word suggests unpredictability and lack of control. When items are scattered randomly across a floor, they're not arranged in rows or sorted by size: they're just wherever they landed. When you randomly bump into a friend at the store, it wasn't planned by either of you.

People sometimes use randomly more loosely in conversation. “I was randomly thinking about dinosaurs today” usually just means unexpectedly or for no particular reason, not that their thoughts were literally determined by chance.