From Proto-Indo-Iranian *ȷ́ā́nu, from Proto-Indo-European *ǵónu.
*jā́nu n
- knee
- Central Iranian:
- Avestan: 𐬰𐬁𐬥𐬎 (zānu), 𐬲𐬥𐬏𐬨 (žnūm, “knee”, acc.pl.)
- Northeastern Iranian:
- Khotanese: [script needed] (ysānū)
- Ossetian: зоныг (zonyg)
- Sogdo-Bactrian:
- Khwarezmian: [script needed] (z’nwk)
- Proto-Sogdic: *zā́nukā (see there for further descendants)
- Southeastern Iranian
- Ormuri-Parachi:
- Ormuri: [script needed] (zānū)
- Parachi: zânū
- Pamir:
- Ishkashimi: [script needed] (zung)
- Shughni: zun
- Pashto: زانو (zānú), زنګون (zengewn)
- Northwestern Iranian:
- Parthian: [script needed] (zʾnwg /zānūg/)
- → Middle Persian: [script needed] (zʾnwg /zānūg/)
- Classical Persian: زانو (zānū)
- Iranian Persian: زانو (zânu)
- Tajik: зону (zonu)
- → Northern Luri: زونی (zoni)