Energy

Definition

Energy is a noun that refers to the capacity for doing work or causing physical change. It can exist in various forms, such as kinetic, potential, thermal, electrical, chemical, and nuclear. In everyday usage, it often describes a person’s mental or physical vitality and enthusiasm.

Parts of Speech

• Noun

Pronunciation

American English

• IPA Pronunciation: /ˈɛnərdʒi/
• Respelling: EN-er-jee

British English

• IPA Pronunciation: /ˈɛnədʒi/
• Respelling: EN-uh-jee

Etymology

The word "energy" originates from the Greek "energeia," meaning "activity" or "operation," from "energos," meaning "active" or "working." It was adopted into Latin as "energia" and entered the English language in the late Middle Ages, originally used to describe vigor or vitality before acquiring scientific meanings.

Derivatives

• Energetic (adjective)
• Energetically (adverb)
• Energy-efficient (adjective)
• Energy-saving (adjective)
• Re-energize (verb)

Synonyms

• Power
• Vitality
• Strength

Antonyms

• Weakness
• Exhaustion
• Fatigue

Usage

The noun "energy" is commonly used in both scientific and everyday contexts. For instance, "Solar panels harness the sun’s energy," and "She has a lot of energy for her age."

Related Terms

• Power: The rate at which energy is transferred or converted.
• Force: A physical influence that causes an object to change its motion or shape.
• Work: The result of a force moving an object over a distance.

Detailed Definitions

Noun

• The capacity for doing work or causing physical change, often measured in joules or calories: Refers to a fundamental property in physics, describing the ability to perform work or produce movement.
  • Example: "The kinetic energy of a moving object increases with its speed."
• Mental or physical vigor and vitality: Describes a person’s level of alertness, enthusiasm, and activity.
  • Example: "She approaches every task with boundless energy."
• A natural resource, such as fuel or electricity, used to provide power: Refers to sources of power for industrial, household, and transportation purposes.
  • Example: "Renewable energy sources are becoming more popular."