D defs.my
Entry 1 sense Webster, 1913

Donjon

/(dŭn"jŭn)/ · Don·jon · IPA /ˈdʌn.d͡ʒən/
01 n. The chief tower, also called the keep; a massive tower in ancient castles, forming the strongest part of the fortifications. See Illust. of…
  1. 1.
    The chief tower, also called the keep; a massive tower in ancient castles, forming the strongest part of the fortifications. See Illust. of Castle. Also: keep See: Castle