规律 (guī lǜ) is a noun meaning 'law', 'pattern', or 'regularity' — referring to consistent, observable principles that govern natural phenomena, human behavior, or abstract systems. The character 规 (guī) originally meant 'compass' or 'rule', suggesting measurement and standard; 律 (lǜ) means 'regulation', 'rhythm', or 'law', often implying order and repetition. Together, they convey the idea of an inherent, repeatable order underlying reality — not just legal statutes, but patterns like seasonal cycles, biological rhythms, or mathematical sequences.

This word appears frequently in scientific, philosophical, and everyday contexts: 'the laws of physics', 'the growth pattern of bamboo', or 'a child’s sleep schedule'. It carries a neutral-to-formal tone and is rarely used in casual speech without context. Unlike the English word 'law', 规律 does not imply enforcement or authority — it describes what *is*, not what *must be*.