消毒
xiāo dú · HSK 5
to disinfect
🧴 消毒 = eliminate + poison
消 means to extinguish or eliminate (as in 消失 disappear); 毒 means poison or toxin. Together: wipe out the germs/toxins, i.e. disinfect or sterilize.
消 — water 氵 + 肖 (phonetic)
消 is a semantic-phonetic compound: the water radical 氵 indicates the meaning, while 肖 (xiào) supplies the sound. It originally described water dwindling or melting away, and from there extended to the modern senses of vanishing, dissolving, and dispelling.
毒 — grass 屮 on top + 母 (mother/below)
Originally an associative compound showing a toxic plant (the 屮/生 element on top) over 毋, suggesting something harmful that must be forbidden. The early meaning was 'poisonous herb,' which broadened to 'poison,' 'toxic,' and figuratively 'cruel' or 'malicious.' The modern form keeps this top-plant + bottom-warning structure.