Godan verb with 'su' ending, Transitive verb
to pollute; to contaminate; to soil; to make dirty; to stain
その本を汚さないように扱ってくれるなら、貸してあげるよ。You may borrow this book as long as you keep it clean. to disgrace; to dishonour; to dishonor; to defile
esp. けがす
Also written 穢す【けがす】