Smirch, v. t.
Etymology: [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.
1 other Webster entry under this spelling
Smirch, n.
A smutch; a dirty stain.
Shades of meaning
Fernald has no entry of its own for smirch; he lists it under blemish.
He lists it without comment; the entries above explain its neighbors.