From The Collaborative International Dictionary of English v.0.48 :
Immurement \Im*mure"ment\, n.
The act of immuring, or the state of being immured;
imprisonment.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
immurement
n 1: the state of being imprisoned; "he was held in captivity
until he died"; "the imprisonment of captured soldiers";
"his ignominious incarceration in the local jail"; "he
practiced the immurement of his enemies in the castle
dungeon" [syn: captivity, imprisonment,
incarceration, immurement]