natural philosophy, physical science, physics - the science of matter and energy and their interactions

physical phenomenon - a natural phenomenon involving the physics of matter and energy

activation energy, energy of activation - the energy that an atomic system must acquire before a process (such as an emission or reaction) can occur; "catalysts are said to reduce the energy of activation during the transition phase of a reaction"

alternative energy - energy derived from sources that do not use up natural resources or harm the environment

atomic energy, nuclear energy - the energy released by a nuclear reaction

binding energy, separation energy - the energy required to separate particles from a molecule or atom or nucleus; equals the mass defect

chemical energy - that part of the energy in a substance that can be released by a chemical reaction

electrical energy, electricity - energy made available by the flow of electric charge through a conductor; "they built a car that runs on electricity"

energy level, energy state - a definite stable energy that a physical system can have; used especially of the state of electrons in atoms or molecules; "according to quantum theory only certain energy levels are possible"

rest energy - the energy equivalent to the mass of a particle at rest in an inertial frame of reference; equal to the rest mass times the square of the speed of light

work - (physics) a manifestation of energy; the transfer of energy from one physical system to another expressed as the product of a force and the distance through which it moves a body in the direction of that force; "work equals force times distance"

heat, heat energy - a form of energy that is transferred by a difference in temperature

mechanical energy - energy in a mechanical form

radiant energy - energy that is transmitted in the form of (electromagnetic) radiation; energy that exists in the absence of matter

radiation - energy that is radiated or transmitted in the form of rays or waves or particles

forcefulness, strength, force - physical energy or intensity; "he hit with all the force he could muster"; "it was destroyed by the strength of the gale"; "a government has not the vitality and forcefulness of a living man"

athleticism, strenuosity - intense energy; "his music is characterized by a happy athleticism"

drive - the trait of being highly motivated; "his drive and energy exhausted his co-workers"

second wind - renewed energy or strength to continue an undertaking; "She had dinner and got a second wind to finish painting"; "the employers, initially taken by surprise at the pace of developments, regained their second wind"

sprightliness, liveliness, spirit, life - animation and energy in action or expression; "it was a heavy play and the actors tried in vain to give life to it"

verve, vitality - an energetic style

good health, healthiness - the state of being vigorous and free from bodily or mental disease

juice - energetic vitality; "her creative juices were flowing"

ch'i, chi, ki, qi - the circulating life energy that in Chinese philosophy is thought to be inherent in all things; in traditional Chinese medicine the balance of negative and positive forms in the body is believed to be essential for good health

executive department - a federal department in the executive branch of the government of the United States

Department of Energy Intelligence, DOEI - an agency that collects political and economic and technical information about energy matters and makes the Department of Energy's technical and analytical expertise available to other members of the Intelligence Community