洗涤剂
xǐ dí jì · HSK 7
detergent
🧼🫧 洗涤 = wash + rinse, 剂 = agent/preparation; the wash-rinse agent = detergent
洗 (xǐ) is the wash in washing your hands, 涤 (dí) means to rinse or cleanse, and 剂 (jì) marks a prepared agent or dose (same 剂 as in 药剂, medicine preparation). Stack them: the prepared wash-rinse agent is detergent.
洗 — water radical 氵 + 先 (xiān)
A semantic-phonetic compound. The water radical 氵 indicates the meaning (washing with water), while 先 supplies the sound, originally close to xiǎn/xǐ. The character has long meant 'to wash' or 'rinse,' and by extension 'to cleanse' or 'wash away.'
剂 — knife radical 刂 + 齐 (qí)
A semantic-phonetic compound. The knife radical 刂 suggests cutting or preparing, while 齐 supplies the sound. Originally it referred to evenly cut or measured doses of medicine, which is why it now means a dose, preparation, or agent (as in medicine or cleaning agents).