Answer: upsilon

AnswerCrossword Clue
UPSILON

20th Greek letter

UPSILON

Greek letter

UPSILON

20th in a series

UPSILON
Tau follower
UPSILON
Meson made up of a bottom quark and its antiquark
UPSILONGreek letter.
UPSILONGreek vowel
UPSILONLetter before phi
UPSILONY lookalike
UPSILON20th letter of the Greek alphabet