n.
Pronunciation: ' ep-s ə - ˌ län, -l ə n
Function: noun
Etymology: Greek e psilon, literally, simple e
Date: 15th century
1 : the 5th letter of the Greek alphabet ― see ALPHABET table
2 : an arbitrarily small positive quantity in mathematical analysis
– ep · si · lon · ic \ ˌ ep-s ə - ' lä-nik \ adjective