The Avestan word nāfa-
Word nāfa-
Meaning navel
See also Homeric Greek: ὀμφαλός ‘navel’
Proto-Indo-European: *h₂nobʰ- ‘nave, navel’

Other words that might be of interest
zānu- ‘jaw’, čarǝman- ‘skin’, zǝrǝd- ‘heart’, sarah- ‘head’, gava ‘hand’, hizū ‘tongue’, staman ‘mouth’, bruuat̰ ‘eyebrow’, ast- ‘bone’, tanū- ‘body’, bāzu ‘arm, leg’, zānu- ‘knee’, xvafəna- ‘sleep’, pad- ‘foot’