1. strongholds or fortified areas that project from the main walls of a fortification
Usage: military architecture
2. institutions, places, or people that strongly defend particular principles, attitudes, or activities
Usage: figurative

Examples

• The castle’s bastions provided excellent defensive positions against attackers.
• Medieval fortresses often featured angular bastions at their corners.
• The university remains one of the last bastions of academic freedom.
• These small towns are bastions of traditional values.
• The organization serves as a bastion for environmental protection.
• Conservative bastions in the region opposed the new legislation.
• The old fortress had five bastions protecting its perimeter.