Arabic

kāˁ-, kūˁ- - condyle, especially bone of the hand that touches the chip or to the articular finger; ankle bone of the foot, end of the bone (BK 2 944)

‘projecting and of the bone of the forearm at the wrist, wrist-join’ [WKAS I 438].

PWS
*ku/aˁ(-at)- - joint; ankle; foot (SED I No. 140)