Greek letter (3 letters)

{ Answer }

CHI

{ Related Clues }

Tai ___
X
Acupuncturist's concern
Frat letter
Greek X
Ho ___ Minh
O'Hare loc.
Phi follower
Phi's follower
Psi's preceder
Soror's letter
" . . . sweetheart of Sigma ___"
"The Sweetheart of Sigma ___"
Trib's home
Bears' home, briefly
Between phi and psi
Greek letter X
Its symbol is X
Japanese kana character
Loop locale, informally
McBride of "Boston Public"
Midwest city, familiarly
Midwest city, for short
O'Hare site, for short
___-square (odds calculation)
___-Town (Cubbies' home)
___-Town (Midwest hub)
White Sox on scoreboards
The Windy City, for short
Windy City, for short
Acupuncturist's vital life force
Home of the Bears and the Bulls: Abbr.
Home of two M.L.B. teams
Mayor Byrne's city, for short
Tai ___ (meditative martial art)
T'ai ___, Oriental martial art

{ Tags }

chi, city, follower, force, greek, home, its, letter, life, midwest, nl, phi, short, sigma, sox, sweetheart, tai, town, white, windy, x

{ Notes }

The answer CHI is seen frequently, appearing about once every 100 puzzles.

{ Definition }

CHI as a noun:

1. (qi, chi, ch'i, ki) = the circulating life energy that in Chinese philosophy is thought to be inherent in all things; in traditional Chinese medicine the balance of negative and positive forms in the body is believed to be essential for good health

2. (chi, khi) = the 22nd letter of the Greek alphabet