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• epsilon
  epsilon

  noun

  the fifth letter of the Greek alphabet (E, ε).
• Epsilon
  Epsilon

  noun

  (foll by the genitive case of a specified constellation) the fifth brightest star in a constellation

epsilon

American  

[ep-suh-lon, -luhn, ep-sahy-luhn] / ˈɛp səˌlɒn, -lən, ɛpˈsaɪ lən /

noun

1. the fifth letter of the Greek alphabet (E, ε).

2. the consonant sound represented by this letter.

3. Mathematics. an arbitrarily small quantity, used to indicate that a given quantity is small, or close to zero.

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Epsilon ¹ British  

/ ˈɛpsɪˌlɒn, ɛpˈsaɪlən /

noun

1. (foll by the genitive case of a specified constellation) the fifth brightest star in a constellation

   Epsilon Aurigae

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epsilon ² British  

/ ˈɛpsɪˌlɒn, ɛpˈsaɪlən /

noun

1. the fifth letter of the Greek alphabet (Ε, ε), a short vowel, transliterated as e

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Etymology

Origin of epsilon

First recorded in 1400–50; from Greek e psīlón “bare, simple e ” (as opposed to diphthongal spellings which in later Greek represented the same sound)

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Example Sentences

See Examples For:

epsilon Epsilon

For the three stars with detected astrospheres, named 70 Ophiuchi, epsilon Eridani, and 61 Cygni, the researchers estimated their mass loss rates to be 66.5±11.1, 15.6±4.4, and 9.6±4.1 times the solar mass loss rate, respectively.

From Science Daily ● Apr. 12, 2024

As an approach, differential privacy is agnostic about how to both choose an overall epsilon value and allocate it across released statistics.

From Slate ● Aug. 12, 2021

A few others made the rogue’s gallery of variants: gamma, beta, epsilon.

From Washington Post ● Aug. 8, 2021

Another delta mutation — also found in kappa and epsilon — is called L452R.

From Salon ● Jul. 29, 2021

There were five city quarters, designated by the Greek letters alpha through epsilon.

From "Circumference" by Nicholas Nicastro

The Alpha Epsilon Pi chapter stated that no one affiliated with the fraternity was involved or complicit in the incident.

From The Wall Street Journal ● Oct. 14, 2026

At the University of Miami, inside the columned fraternity house of Sigma Alpha Epsilon, one brother had some valuable information.

From The Wall Street Journal ● Mar. 6, 2026

Named Epsilon Indi, the star is the smallest and coolest dwarf star yet observed with solar-like oscillations -- "starquakes" like those shown by the Sun.

From Science Daily ● Mar. 26, 2024

Besides making traditional ads, Publicis is well invested in data and tech through its units Epsilon and Sapient, which employ online consumer data to help clients build marketing strategies.

From Reuters ● Oct. 12, 2023

“But to answer your question. There were five in my Epsilon unit.”

From "The Last Cuentista" by Donna Barba Higuera

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