What is "immuring"

Immure \Im*mure"\, v. t. [imp. & p. p. Immured; p. pr. & vb. n. Immuring.] [Pref. im- in + mure: cf. F. emmurer.]

1. To wall around; to surround with walls. [Obs.]
   --Sandys.

2. To inclose whithin walls, or as within walls; hence, to shut up; to imprison; to incarcerate.

   Those tender babes Whom envy hath immured within your walls.
   --Shak.

   This huge convex of fire, Outrageous to devour, immures us round.
   --Milton.

n. The act of wall up. vb. (present participle of immure English)