The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. To inclose whithin walls, or as within walls; hence, to
      shut up; to imprison; to incarcerate.
      [1913 Webster]

            Those tender babes
            Whom envy hath immured within your walls. --Shak.
      [1913 Webster]

            This huge convex of fire,
            Outrageous to devour, immures us round. --Milton.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Immure \Im*mure"\, n.
   A wall; an inclosure. [Obs.] --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

immure
    v 1: lock up or confine, in or as in a jail; "The suspects were
         imprisoned without trial"; "the murderer was incarcerated
         for the rest of his life" [syn: imprison, incarcerate,
         lag, immure, put behind bars, jail, jug, gaol,
         put away, remand]