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