kuḏ̣r- - hollow at the top of the chest, between the two collarbones
(BK 2 905,)
only with the meaning ‘cushion of fat (of a part of the vulva, of the fat around kidneys)’ [WKAS I 224]
PS
*ki/uṯ̣r- - joint (of the ribs, fingers, etc.)
(SED I No. 155)
Though reconstructed as an anatomic term on the PS level, the present root is likely related to, or rather derived from, Sem. *k(ʷ)ṯ̣r ‘to bind, knot, fix’