Vigor

vigor
1. Physical or mental strength, energy, or force.
2. The capacity for natural growth and survival, as of plants or animals.
3. Strong feeling; enthusiasm or intensity.
4. Legal effectiveness or validity.

1. active strength or force; intensity; energy.
2. healthy physical or mental energy or power; vitality.
3. healthy growth in any living matter or organism, as a plant.
4. effective force, esp. legal validity.