Proto-Indo-European root meaning "the hand." 

It forms all or part of: chiral; chiro-; chirognomy; chirography; chirology; chiromancy; chiropodist; chiropractic; chiropractor; chirosophy; chirurgeon; enchiridion; surgeon; surgery; surgical.

It is the hypothetical source of/evidence for its existence is provided by: Greek kheir, Hittite keshshar, Armenian jern "the hand" 

"the supposed science of judging character from the lines and marks of the hand," 1868, from chiro- "hand" + -gnomy, from Greek gnome "judgment, opinion," from PIE root *gno- "to know." Related: Chirognomist.

"handwriting, the art of writing," 1650s, from chiro- "the hand"+ -graphy "writing." Chirograph "formal written legal document" is attested from late 13c. in Anglo-French, from Latin chirographum, from Greek kheirographia "written testimony." Related: Chirographer; chirographic.

"art or practice of finger-spelling, use of the manual alphabet," 1650s, from chiro- "hand" + -logy "a speaking."

"one who treats diseases or malformations of the hands or feet," 1785, from chiro- "hand" + pod-, stem of Greek pous "foot" (from PIE root *ped- "foot") + -ist. Probably coined by Canadian-born U.S. healer Daniel Palmer (1845-1913); originally they treated both hands and feet. A much-maligned word among classicists, who point out it could mean "having chapped feet" but probably doesn't, and in that case it is an etymological garble and no one can say for sure what it is meant to signify. Related: Chiropody.

in reference to the curing of diseases by manipulation of the spine or other bodily structures, coined in American English, 1898 (adj.); 1899 (n.), from chiro- "hand" + praktikos "practical" (see practical), the whole of it loosely meant as "done by hand."

"knowledge of character and possible future based on the lines and marks of the hand," 1885, from chiro- "the hand" + -sophy "knowledge."