ats.tsil denotes bodily joints in contexts involving wrists or arms, and also a joint in a building measurement.

The attested uses chiefly concern bodily joints: plural construct forms occur with wrists in Ezekiel 13:18 and with arm joints beneath ropes in Jeremiah 38:12. A singular form marks a joint within the measured structure of the house in Ezekiel 41:8.

1. Bodily joint or joint area · dominant

   In Ezekiel 13:18, the plural construct form occurs in the clause about sewing amulets on all wrists; the APB renders the setting with “wrists.” In Jeremiah 38:12, the plural construct form is in Ebed-melech's instruction to place rags and clothes under Jeremiah's arm joints beneath the ropes; the APB renders “arm joints.”

   Ezekiel 13:18Jeremiah 38:12
2. Structural joint in a measurement · occasional

   In Ezekiel 41:8, the singular absolute form occurs at the end of the house's stated measurement, from the foundations of the sides to its full extent. The APB renders the measurement as “six cubits to the joint.”

   Ezekiel 41:8

In the Anselm Project Bible: The APB presents the term with “wrists,” “arm joints,” and “joint” across these verses. These renderings confirm the clauses' settings rather than establish separate English equivalents.