shackle joint

shackle joint (plural shackle joints)

1. (anatomy) A joint formed by a bony ring passing through a hole in a bone, as at the bases of spines in some fishes.
2. A joint held together by a shackle or clevis and a bolt.
   • 1818, The Repertory of Arts, Manufactures, and Agriculture, page 266:

     The screw 22, which actuates the rod 19 of the piston, passes through the screw 23, and is jointed to the end of the rod 19 by a shackle joint;