Daub, n.
1. A viscous, sticky application; a spot smeared or dabed; a smear.
2. (Paint.)
A picture coarsely executed. Did you . . . take a look at the grand picture . . . 'T is a melancholy daub, my lord. Sterne.
2 other Webster entries under this spelling
Daub, v. t. [imp. & p. p. Daubed; p. pr. & vb. n. Daubing.]
1. To smear with soft, adhesive matter, as pitch, slime, mud, etc.; to plaster; to bedaub; to besmear. She took for him an ark of bulrushes, and daubed it with slime and with pitch. Ex. ii. 3.
2. To paint in a coarse or unskillful manner. If a picture is daubed with many bright and glaring colors, the vulgar admire it is an excellent piece. I. Watts. A lame, imperfect piece, rudely daubed over. Dryden.
3. To cover with a specious or deceitful exterior; to disguise; to conceal. So smooth he daubed his vice with show of virtue. Shak.
4. To flatter excessively or glossy. [R.] I can safely say, however, that, without any daubing at all, I am very sincerely your very affectionate, humble servant. Smollett.
5. To put on without taste; to deck gaudily. [R.] Let him be daubed with lace. Dryden.
Daub, v. i.
To smear; to play the flatterer. His conscience . . . will not daub nor flatter. South.
Shades of meaning
Fernald has no entry of its own for daub; he lists it under blemish.
He lists it without comment; the entries above explain its neighbors.