1. a fundamental principle or basic assumption
Usage: formal; academic
2. a starting point or beginning
Usage: formal; philosophical

Examples

• The principium of his argument was flawed from the start.
• She questioned the basic principium underlying the theory.
• The philosopher traced the concept back to its principium.
• Without a solid principium, the entire system would collapse.
• The principium of causality is central to scientific inquiry.
• They debated the principium of individual rights versus collective good.