1) Asperse 2) Badmouth 3) Besmirch 4) Besoil 5) Blot 6) Blotch 7) Calumniate 8) Defame 9) Fingermark 10) Inkblot 11) Splodge 12) Splotch 13) Traduce 1) Blemish 2) Blot 3) Daub 4) Defect 5) Discredit 6) Discrediting act 7) Dishonor 8) Slur 9) Smear 10) Smudge 11) Soil 12) Spot 13) Sully 14) Tarnish 15) To dirty 16) To harm the reputation of 17) To make dirty 18) To smear or slander 
• (v. t.) To smear with something which stains, or makes dirty; to smutch; to begrime; to soil; to sully. • (n.) A smutch; a dirty stain.
Smirch noun A smutch; a dirty stain. Smirch transitive verb [ From the root of smear .] To smear with something which stains, or makes dirty; to smutch; to begrime; to soil; to sully. « I'll . . . with a kind of umber smirch my face.» Shak. 
[v] - smear so as to make dirty or stained
verb smear so as to make dirty or stained