What does "defilement" mean?

Defilement: The protection of the interior walls of a fortification from an enfilading fire, as by covering them, or by a high parapet on the exposed side.

Additional senses

  1. 2.The act of defiling, or state of being defiled, whether physically or morally; pollution; foulness; dirtiness; uncleanness. Defilements of the flesh. Hopkins. The chaste can not rake into such filth without danger of defilement. Addison.

Sources