WordNet sense 1 (a healthy capacity for vigorous activity):

energy, vim

WordNet sense 2 ((biology) a hypothetical force (not physical or chemical) once thought by Henri Bergson to cause the evolution and development of organisms):

life force, elan vital, vital force

WordNet sense 3 (the property of being able to survive and grow):

animation

WordNet sense 4 (an energetic style):

verve