Definition

1. Noun:
   • The fifth letter of the Roman alphabet: "E" is the fifth letter in the modern English alphabet and the Latin script.
   • A mathematical constant: "e" is the base of the natural logarithm, an irrational and transcendental number approximately equal to 2.71828.
   • A cardinal direction: "E" is the abbreviation for the cardinal compass point East, which is at 90 degrees on a compass.
   • A chemical element: "E" is the symbol for einsteinium, a synthetic, radioactive transuranic element.
   • A vitamin: "E" refers to Vitamin E, a group of fat-soluble compounds that act as antioxidants.

Usage Examples

• Noun:
  • The word "example" begins with the letter e.
  • The mathematical constant e is fundamental to calculus.
  • The map indicated that the city was located to the E.
  • The scientist studied the properties of the element e (einsteinium).
  • Foods like almonds and spinach are rich in Vitamin E.

Advanced Usage

• In mathematics: "e" is often used in formulas for exponential growth, compound interest, and complex analysis.
  • The function f(x) = e^x is its own derivative.
• In computing: "E" or "e" can be used as a variable name or in scientific notation.
  • The program stored the value as 1.6e-19.
• In music: "E" is the name of a musical note, the third note in the C major scale.

Variants and Related Words

• E- (prefix): Used to denote electronic or internet-based versions of things.
  • e-commerce, e-mail
• E (abbreviation): Can stand for various terms like "energy" (in physics) or "exa-" (a prefix in the metric system denoting 10^18).

Synonyms

• East: For the cardinal direction.
• Einsteinium: For the chemical element (symbol Es).
• Vitamin E: For the nutrient (also called tocopherol).

Related Phrases

• E = mc²: Albert Einstein's famous mass-energy equivalence formula from the theory of relativity.
• E-ticket: Originally a paperless airline ticket, now often refers to any electronic pass or reservation.

Noun

1. the 5th letter of the Roman alphabet
2. the base of the natural system of logarithms; approximately equal to 2.718282...
3. the cardinal compass point that is at 90 degrees
4. a radioactive transuranic element produced by bombarding plutonium with neutrons
5. a fat-soluble vitamin that is essential for normal reproduction; an important antioxidant that neutralizes free radicals in the body