energy
UK: ˈenədʒi | US: ˈenərdʒi
n. the capacity for vigorous activity; available power
n. (physics) the ability to do work, measured in joules
n. a feeling of enthusiasm or determination
The word "energy" originates from Greek energeia (ἐνέργεια), formed by en- (in) + ergon (work). It entered Late Latin as energia, then Middle French as énergie, before being adopted into English in the 16th century. Originally, it described philosophical or spiritual "force in action," later evolving into its modern scientific sense (ability to do work) in the 19th century. The morpheme erg persists in related terms like ergonomics (work-study) and synergy (combined work).
Solar energy is a sustainable alternative to fossil fuels.
She tackled the project with boundless energy.
The law of conservation of energy states it cannot be created or destroyed.
After coffee, I felt a surge of energy.
His speech lacked energy and failed to inspire the audience.