- 1 an area in which there is a lot of support for a particular belief or group of people, especially a political party a Republican stronghold/a stronghold of Republicanism The Democratic Party retained its traditional stronghold in the northeast. The college is a stronghold of the child-centered approach to teaching.
- 2a castle or a place that is strongly built and difficult to attack The castle was an important royal stronghold for hundreds of years. Troops surrounded the mountain stronghold of the guerrillas.
- 3an area where there are a large number of a particular type of animal This valley is one of the last strongholds of the Siberian tiger.