Why “immurement” is a great word
A state or act of entombing or sealing a person alive within a structure of walls, a form of capital punishment or life imprisonment. From the verb 'immure' (from Medieval Latin *immūrāre*, from Latin *in-* 'in' + *mūrus* 'wall') + the English noun-forming suffix *-ment*. Unlike 'incarceration,' a general term for imprisonment, or 'solitary confinement,' which speaks to psychological isolation, immurement is the permanent, physical act of becoming one with the architecture of your own doom. It is the nun sealed into her anchorhold with only a squint to the chapel, the victim bricked into a niche whose mortar sets slowly enough to hear the last prayers, the unfortunate buried upright in the foundation of a new tower—an architecture of erasure where stone replaces witness, and the condemned vanishes not into darkness but into structure itself, becoming part of what stands after they cease to stand at all.
Definitions & examples from Wiktionary (CC BY-SA 3.0).