熬制 (áo zhì) is a compound verb meaning 'to prepare (a medicine, herbal decoction, or concentrated extract) by slow, prolonged simmering over low heat.' The first character 熬 (áo) means 'to simmer for a long time' or 'to endure through hardship,' emphasizing the extended heating process; the second character 制 (zhì) means 'to make, prepare, or manufacture.' Together, they specifically describe the traditional method used in Chinese herbal medicine and food therapy to extract active ingredients from roots, barks, or herbs by boiling them gently for hours.

This term is almost exclusively used in health-related contexts — especially in traditional Chinese medicine (TCM), pharmacy, and home remedies. It implies careful attention, precise timing, and often multiple stages of straining and reducing. While it can occasionally appear in gourmet cooking (e.g.,熬制高汤), its primary domain remains medicinal preparation, distinguishing it from general cooking verbs like 煮 (boil) or 炖 (braise).