Definition of "energy" []

• The capacity for work or vigorous activity; vigor; power. See Synonyms at strength. (noun)
• Exertion of vigor or power: a project requiring a great deal of time and energy. (noun)
• Vitality and intensity of expression: a speech delivered with energy and emotion. (noun)
• Usable heat or power: Each year Americans consume a high percentage of the world's energy. (noun)
• A source of usable power, such as petroleum or coal. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Dr. Karl offers compelling counter-arguments to some of the speculations of the BPP, although he points us toward the controversial energy source of * zero point energy* as the breakthrough discovery we can use to power our starships."
• "Rather, conventional energy strategies adopt the ‘energy trickle-down’ approach to social welfare and implicitly assume that if energy supplies are increased, these problems will take care of themselves."
• "Take, for example, the two most important terms - the energy released by the fire and the energy recovered by the pot contents (“energy utilised” in the literature)."