Epsilon meaning : The name for the fifth letter of the Greek alphabet, ε or Ε, preceded by delta (Δ, δ) and followed by zeta (Ζ, ζ). In IPA, the phonetic symbol ɛ that represents the open-mid front unrounded vowel. An arbitrarily small quantity. A negligible effect. The percentage change in an option value with respect to the underlying dividend yield.