also: エプシロン
noun
epsilon
The Greek letter Ε/ε; used in mathematics, physics, and other sciences.
数学で、εは非常に小さな正の数を表すことが多い。
In mathematics, ε often represents a very small positive number.
noun
Epsilon rocket
A Japanese solid-fuel rocket developed by JAXA; named after the Greek letter.
イプシロンロケットは、小型衛星の打ち上げに使われる。
The Epsilon rocket is used to launch small satellites.
From Greek ἒ ψιλόν (e psilon), meaning 'simple e' or 'bare e'. The rocket name is derived from the letter.