# epsilon

> English word · Noun · IPA /ɛpˈsaɪ.lən/ · frequency rank #33,640

## Definitions
1. The fifth letter of the Greek alphabet, ε or Ε, preceded by delta (Δ, δ) and followed by zeta (Ζ, ζ).
2. In IPA, the phonetic symbol ɛ that represents the open-mid front unrounded vowel.
3. An arbitrarily small quantity.
4. An arbitrarily small quantity.
5. Something negligible or insignificant.
6. The percentage change in an option value with respect to the underlying dividend yield.

## Etymology
From Ancient Greek ἒ ψιλόν (è psilón, “simple Ε”).

## Common misspellings (10)
`epislon`, `eppsilon`, `epsillon`, `epsilno`, `epsilonn`, `epsioln`, `epslion`, `epssilon`, `espilon`, `pesilon`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/epsilon