/sit"euh dl, -euh del'/ , n.
1. a fortress that commands a city and is used in the control of the inhabitants and in defense during attack or siege.
2. any strongly fortified place; stronghold.
3. (formerly) a heavily armored structure on a warship, for protecting the engines, magazines, etc.
[ 1580-90; citadelle cittadella, equiv. to cittad ( e ) CITY + -ella -ELLE ]