with obj.
1- make (something) dirty; soil弄脏：
the window was smirched by heat and smoke.
窗户被热气和烟雾弄脏了。
1.1
- figurative discredit (a person or their reputation); taint〈喻〉污蔑; 诋毁（人, 名誉）：
I am not accustomed to having my honour smirched.
我不习惯于自己的荣誉被人玷污。
1
- a dirty mark or stain污点, 污斑。
1.1
- figurative a blot on someone's character; a flaw〈喻〉（名声、人格上的）污点; 缺点, 瑕疵。
词源
late 15th cent.: probably symbolic.