(of a person) the force, strength, capacity, to do things and get things done
person's spirit and vigor
Cases of word usage
1) showing or having no interest, energy etc (apathetic)
2) needing and using much energy and thought (arduous)
3) to give (one's time, energy etc) (to a special cause or purpose) (dedicate)
4) to give up one's time, energy etc to something (devote)
5) a machine used for changing steam-power, water-power etc into electrical energy (dynamo)
6) (an attempt at) trying hard; use of strength and energy (to do something) (effort)
7) full of, done with, energy (energetic)
8) any kind of machine that changes energy (from petrol, electricity etc) into motion (engine)
9) without energy or force (feeble)
10) (of a person) wasting time, energy etc in their work or duties (inefficient)