chi; Χ, χ +

(Greek: twenty-second letter of the Greek alphabet; Χ, χ)

chi, khi
The 22nd letter of the Greek alphabet, represented in English as ch or kh and transliterated into Latin as ch.
chiasma (s) (kigh AZ muh) (noun), chiasmata (kigh AZ muh tuh) (pl)
1. A crossing; two things placed cross-wise.
2. In anatomy, the crossing over of body parts; any crossing over of biological tissue.
3. A crossing or intersection of the optic nerves on the ventral surface of the brain.
4. Etymology: Mid-19th century via modern Latin from Greek khiasma, "crosspiece", from khiazein, "mark with an X"; from khi, "the (Greek) letter chi".
chiasmatypy (kigh AZ muh tigh" pee) (s) (noun) (no plural form)
A twisting of homologous chromosomes around each other during one state of meiosis, resulting in a possible interchange of genes by the chromosomes.
chiasmus (s) (noun) (kigh AZ muhs), chiasmi (kigh AZ migh) (pl)
A rhetorical construction in which the order of the words in the second of two paired phrases, clauses, etc., are in the reverse order of the first one: "The construction of chiasmi consist of inversions of the second of two parallel structures of word orders."

Examples of chiasmi:

It [marriage] may be compared to a cage: the birds without try desperately to get in, and those within try desperately to get out.
—Michel de Montaigne, on marriage
It is not my interest to pay the principal nor is it my principle to pay the interest.
—Richard Brinsely Sheridan, to a lender
Resolve to perform what you ought; perform without fail what you resolve.
—Benjamin Franklin
Try to learn something about everything and everything about something.
—Thomas H. Huxley
The error of youth is to believe that intelligence is a substitute for experience, while the error of age is to believe that experience is a substitute for intelligence.
—Lyman Bryson
All misanthropes are curmudgeons, but all curmudgeons are not misanthropes.
—Florence King
The secret of happiness is not in doing what one likes, but in liking what one has to do.
—James Barrie, author and educator from Scotland
Not all readers become leaders, but all leaders must be readers.
—Harry S. Truman, 33rd President of the United States
—Compiled from Never Let a Fool Kiss You or a Kiss Fool You
by Dr. Mardy Grothe; Published by Viking; a member of the Penguin Group;
New York; 1999.
chiastic (adjective), more chiastic, most chiastic
Pertaining to, or characterized by the inversion of the second of two parallel structures.

You can see all of the letters of the Greek Alphabet on this page.