The Avestan word ast-
Word ast-
Meaning bone
See also Armenian: oskr ‘bone’
Proto-Indo-European: *h₂óst ‘bone’
Greek: οστόν ‘bone’

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