The Collaborative International Dictionary of English v.0.48:

Inwall \In*wall"\ ([i^]n*w[add]l"), v. t. [imp. & p. p.
   Inwalled ([i^]n*w[add]ld"); p. pr. & vb. n. Inwalling.]
   To inclose or fortify as with a wall. --Spenser.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Inwall \In"wall`\ ([i^]n"w[add]l`), n.
   An inner wall; specifically (Metal.), the inner wall, or
   lining, of a blast furnace.
   [1913 Webster]