1. a fundamental truth or rule that serves as the foundation for a system of belief or behavior
2. a moral rule or standard of good behavior
3. a basic scientific rule or law that explains how something works
Usage: scientific

Examples

• The principle of equality is fundamental to democracy.
• She refused to compromise her principles for money.
• The school operates on the principle that all students can succeed.
• He’s a man of principle who always does what’s right.
• The principle of gravity explains why objects fall to earth.
• This machine works on the same principle as a lever.
• The company’s guiding principles include honesty and integrity.