Vigorous means full of energy, strength, and enthusiasm. When you give something a vigorous effort, you're putting real muscle and determination into it: scrubbing a dirty pot vigorously, shaking a snow globe with vigorous motion, or defending your position in a debate with vigorous arguments.

The word describes both physical energy and mental intensity. A vigorous hike pushes your body with steep climbs and a quick pace. A vigorous discussion means people are engaging deeply and passionately with ideas, challenging each other's thinking and exploring topics thoroughly. Plants grow vigorously when they're healthy and thriving, shooting up new leaves and stems.

Vigorous implies strength and robustness combined with active energy. A vigorous workout leaves you breathing hard. A vigorous defense of an innocent person shows both passion and power. When a teacher leads a vigorous class discussion, students are actively participating, challenging ideas, and thinking hard.

The opposite of vigorous would be weak, halfhearted, or listless. If you approach a challenging project vigorously, you're tackling it with real force and commitment, not tiptoeing around it.