Hoop lock

the fastening for uniting the ends of wooden hoops by notching and interlocking them.

See also: Hoop

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
The friends hover over the globe as they speak lines that feminize the earth ("the whole earth / Is but a prisoner, nor the sea her jailor, / That with a silver hoop locks in her body"), underscoring the equation between the lady and the kingdom occurring in the main plot as well.