In'wall` (ĭn'wal`) noun An inner wall; specifically (Metal.) , the inner wall, or lining, of a blast furnace. Found on http://www.encyclo.co.uk/webster/I/94
In·wall' (ĭn*wal') transitive verb [ imperfect & past participle Inwalled (-wald'); present participle & verbal noun Inwalling .] To inclose or fortify as with a wall. Spenser. Found on http://www.encyclo.co.uk/webster/I/94