Energy
noun (pl. energies)
1 the strength and vitality required for sustained physical or mental activity: changes in the levels of vitamins can affect energy and well-being.
•(energies) a person's physical and mental powers, typically as applied to aparticular task or activity.
2 power derived from the utilization of physical or chemical resources, esp. to provide light and heat or to work machines.
3 Physics the property of matter and radiation that is manifest as a capacity toperform work (such as causing motion or the interaction of molecules): a collision in which no energy is transferred.
•a degree or level of this capacity possessed by something or required by a process.
ORIGIN mid 16th cent. (denoting force or vigor of expression): from French énergie, or via late Latin from Greek energeia, from en- 'in, within+ergon'work.'