First of the ten Heavenly Stems; used to indicate the first position in a sequence or rank, often equivalent to "A" or "I" in English lists; ancient Chinese compass point (75°)

General name for mineral salts such as niter or saltpeter; often used to make gunpowder, fertilizer, or medicine

(bound form) used in chemical terms for azole compounds, often appearing in transliterated names of organic compounds like 咔唑 kǎ​zuò or 噻唑 sāi​zuò