Answer:

epsilon

Answer	Crossword Clue
EPSILON	Greek letter
EPSILON	Delta follower
EPSILON	Greek "Wheel of Fortune" buy?

EPSILON	Letter before zeta
EPSILON	Campus letter
EPSILON	Fifth Greek letter
EPSILON	Fifth in a certain series
EPSILON	Delta-zeta connection
EPSILON	Greek vowel
EPSILON	Frat letter
EPSILON	Greek letter.

EPSILON	Between delta and zeta.
EPSILON	Fraternity letter
EPSILON	Small quantity symbol, in math
EPSILON	Electromotive force symbol
EPSILON	Symbol of electromotive force
EPSILON	Fifth star in a constellation
EPSILON	Elasticity symbol, in economics
EPSILON	Leader of ancient Ephesus?

EPSILON	Fifth in a Greek series
EPSILON	Before zeta
EPSILON	Small quantity, in math
EPSILON	Delta neighbor
EPSILON	Lowest caste in "Brave New World"
EPSILON	Fifth of 24 letters
EPSILON	Start of Euripides' signature