It's equivalent to chocho, but a little more less derogative and mainly used by women (not duchesses or princesses, of course), especially in the intimacy with other women.
It can be used as an exclamation of despise if used with the verb "to sweat", but it would sound very rude, so don't use this expression in front of your aunt or your mother's peers
- What you say makes my chichi sweat, asshole!
2) DAMN, THEM IS SOME BIGASS CHI CHI's!
3) Chi Chi DaiSuki!