1. capable of being defended or protected against attack or harm
2. able to be justified or supported by argument or evidence

Examples

• The fortress was built on defendable high ground.
• His position in the debate was defendable with solid evidence.
• The company's decision to raise prices is defendable given rising costs.
• The castle's walls made it a defendable stronghold.
• Her argument, while controversial, is defendable from a legal standpoint.
• The narrow pass was defendable by a small force against a much larger army.