Vigorously means doing something with great energy, strength, and enthusiasm. When you stir cake batter vigorously, you're mixing it with real force and speed, putting muscle into each rotation of the spoon. When a lawyer argues a case vigorously, she's presenting her arguments with passion and conviction, fully committed to making her point.

The word captures both physical energy and intensity of effort. A dog shaking water off its fur does it vigorously, sending droplets flying everywhere. A scientist might vigorously defend her research findings when other scientists question them, showing she truly believes in her work and will stand up for it.

Notice that vigorous action isn't wild or careless. When you shake a bottle of salad dressing vigorously, you're using controlled strength to mix the ingredients thoroughly. The word suggests purposeful energy: you're putting real effort into what you're doing because you want results. Whether someone exercises vigorously, applauds vigorously after a great performance, or vigorously scrubs a dirty pot, they're throwing themselves into the task with commitment and energy.