1. The fifth letter and second vowel of the Greek alphabet (Ε, ε) equivalent to the English short e.
2. As a numeral, it refers to to 5; relating to the fifth member of a particular ordered set.
3. In mathematics, an arbitrarily small quantity, used to indicate that a given quantity is small, or close to zero.

In astronomy, the name for Uranus' most distant and most visible ring.

A neutral scalar meson resonance with positive charge conjugation parity and an approximate mass of 1200 MeV (mega-electron volts).

The hexagonal close-packed structure for the epsilon phase of an electron compound.

A bacterial toxin produced by clostridium perfringens or anaerobic Gram-positive rod bacterium that produces epsilon toxin.

It causes intense abdominal cramps and diarrhea that begins 8-22 hours after consumption of foods containing large numbers of these bacteria.

A synthetic substance used to correct an overdose of certain fibrinolytic agents (causing the dissolution of fibrin or blood-clotting by enzymatic action or a chemical that is produced by living cells which is a biochemical catalyst).

It is also useful in treating excessive bleeding due to increased fibrinolytic activity in the blood.

Referring to a method or proof in calculus involving arbitrarily small numbers.

1. The set of all points whose distance from a given point is less than some specified number epsilon.
2. The term epsilon neighborhood (or ε-neighborhood) is often used to emphasize that ε is arbitrarily small.