香油
xiāng yoú · HSK 7
sesame oil
🫗 香 (fragrant) + 油 (oil) = the fragrant oil, i.e. sesame oil
香 means fragrant or aromatic and 油 means oil, so 香油 is literally fragrant oil. In the kitchen this almost always refers to the toasted sesame oil drizzled on finished dishes for its strong nutty aroma.
香 — grain 禾 over sun 日 (originally 甘 'sweet')
Originally an ideograph showing grain (禾) over a vessel of sweet/savory taste (甘), depicting the aroma of cooked millet. Over time the lower 甘 was simplified to 日. The character broadened from 'fragrance of grain' to any pleasant smell, and by extension 'incense' and 'delicious'.
油 — water radical 氵 + 由 (yóu, phonetic)
油 is a phono-semantic compound. The 氵 radical signals a liquid, while 由 supplies the sound. Originally referring to a river name, it was extended to mean oil or fat — any thick, flowing liquid — which became its dominant modern sense.