[ˈɛnədʒi], (Noun)

Definitions:
- the strength and vitality required for sustained physical or mental activity
(e.g: changes in the levels of vitamins can affect energy and well-being)

- power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines
(e.g: nuclear energy)

- the property of matter and radiation which is manifest as a capacity to perform work (such as causing motion or the interaction of molecules)
(e.g: a collision in which no energy is transferred)


Phrases:

Origin:
mid 16th century (denoting force or vigour of expression): from French énergie, or via late Latin from Greek energeia, from en- ‘in, within’ + ergon ‘work’