Douglas Harper's Etymology Dictionary
chiro-
before verbs chir-, word-forming element meaning "hand," from Latinized form of Greek kheiro-, comb. form of kheir (genitive kheiros) "the hand," from PIE *ghes- "hand" (cognates: Hittite keshshar, Armenian jern "hand").
Wiktionary
chiro-
pre. (non-gloss A prefix meaning “hand.” English)