Where does “nombril” come from?

nombril (Middle French) comes from Old French nonbril, from Latin umbilīculus, from Latin umbilīcus, from Proto-Indo-European *h₃nóbʰōl.

nombril (Middle French): belly button

Definitions

Step	Language	Word	Meaning
1	Old French	nonbril	belly button; navel
2	Latin	umbilīculus	—
3	Latin	umbilīcus	—
4	Proto-Indo-European	*h₃nóbʰōl	—

nombril — Etymology, Origin & Word History | Etymology Explorer