腐蚀
fǔ shí · HSK 7
to corrode
🦠 腐 = rot + 蚀 = eat away; together: rot that eats away (corrosion)
腐 (fǔ) is the rot/decay character (think tofu 豆腐, fermented bean). 蚀 (shí) means to eat away or erode, with the 虫 insect radical hinting at bugs gnawing. Combined, 腐蚀 is decay that eats away — chemical corrosion or moral corruption.