Jewish Babylonian Aramaic
ḳiṭrā - joint
(Jastrow 1358)
The basic meaning given by Jastrow is ‘knot’, but the meaning ‘joint’ clearly follows from some of the contexts; ḳṭr, pl. ḳyṭryn ‘joint (of fingers)’ [DJPA 488] (the first meaning is ‘knot’, also ‘node of a plant’).