'原则' (yuán zé) is a compound noun meaning 'principle' or 'fundamental rule'—a basic, guiding standard that informs decisions and behavior. The first character 原 (yuán) means 'original', 'primary', or 'fundamental'; the second character 则 (zé) means 'rule', 'norm', or 'law'. Together, they emphasize an unchanging, foundational truth or standard—not just any guideline, but one considered essential and non-negotiable. It’s commonly used in formal, ethical, academic, or organizational contexts: for example, scientific principles, moral principles, or company operating principles.

This word carries weight and formality; it rarely appears in casual daily speech about minor preferences. It often appears in phrases like '基本原则' (basic principle), '基本原则' (core principle), or '坚持原则' (to uphold one’s principles). Unlike more flexible terms like '规则' (guīzé, 'rule') or '办法' (bànfǎ, 'method'), '原则' implies moral or logical necessity—not mere convention or convenience.