smirch

 
Pronunciation: /sməːtʃ/

verb

[with object]
  • make (something) dirty; soil: the window was smirched by heat and smoke
  • discredit (a person or their reputation); taint: I am not accustomed to having my honour smirched

noun

  • a dirty mark or stain.
  • a blot on someone’s character; a flaw.

Origin:

late 15th century: probably symbolic