The Proto-Indo-European root was *ǵenu- "jawbone, chin" (not to be confused with its homophone *ǵenu- "knee"). The form *ǵenw- became Proto-Germanic *kinnuz, then Old English ċinn, then English chin.
The variant form *ǵ(h)enu- became Sanskrit हनु hanu "jaw". हनुमान hanumān means "having strong jaws". The monkey-god Hanuman was given this name probably because of the story of how Indra struck and injured Hanuman's chin.