1. n. The impetus behind all motion and all activity.
2. n. The capacity to do work.
3. n. (physics) A quantity that denotes the ability to do work and is measured in a unit dimensioned in mass × distance²/time² (ML²/T²) or the equivalent.
Units:
SI: joule (J), kilowatt-hour (kW·h)
CGS: erg (erg)
Customary: foot-pound-force, calorie, kilocalorie (i.e. dietary calories), BTU, liter-atmosphere, ton of TNT
4. n. An intangible, modifiable force (often characterized as either 'positive' or 'negative') believed in some New Age religions to emanate from a person, place or thing and which is (or can be) preserved
5. n. (RPG, video games, board games) A measure of how many actions a player or unit can take; in the fantasy genre often called magic points or mana.
