'Donjon' definitions:

Definition of 'donjon'

From: WordNet
noun
The main tower within the walls of a medieval castle or fortress [syn: keep, donjon, dungeon]

Definition of 'Donjon'

From: GCIDE
  • Donjon \Don"jon\ (d[u^]n"j[u^]n), n. [See Dungeon.] The chief tower, also called the keep; a massive tower in ancient castles, forming the strongest part of the fortifications. See Illust. of Castle. [1913 Webster]