Energy

How to spell energy

6 letters · 3 syllables

How to pronounce energy

Say the part in capitals loudest.

What does energy mean?

1. nounThe strength and vitality needed for sustained physical or mental activity.
2. nounThe measurable capacity of a system to do work, or the power obtained from physical or chemical sources.

Energy in a sentence

• After a full night of sleep she had the energy to finish the report.

• The council voted to invest in renewable energy such as wind and solar.

• The new manager brought fresh energy and enthusiasm to the team.

• Insulating the loft cut the household energy bills sharply.

Where does energy come from?

Language of origin: Greek

This word traces back to the Greek energeia, meaning 'activity' or 'operation', which the philosopher Aristotle coined for the idea of being actively at work. It was built from energos, 'active' or 'at work', combining en, meaning 'in', with ergon, the ordinary Greek word for 'work' or 'deed'. The same ergon root still powers modern coinages such as 'erg' (a unit of work) and the 'ergo' in 'ergonomics'. The term passed through Late Latin energia before entering English in the late 1500s, at first carrying the abstract sense of vigour of expression. By the 1800s physicists had borrowed it for the precise scientific meaning of the capacity to do work. Remembering the buried ergon, 'work', is a neat way to fix the middle of the spelling, since the 'erg' sits literally at the heart of the word.

How the word is built

• en- (in)
• erg (from Greek ergon: work)
• -y (noun suffix)