mistake,
error,
fault a wrong action attributable to bad judgment or ignorance or inattention; "he made a bad mistake"; "she was quick to point out my errors"; "I could understand his English in spite of his grammatical faults"
blot -
a blemish made by dirt; "he had a smudge on his cheek"
tarnish,
maculate,
defile,
sully,
stain make dirty or spotty, as by exposure to air; also used metaphorically; "The silver was tarnished by the long exposure to the air"; "Her reputation was sullied after the affair with a married man"
bespeckle,
speckle mark with small spots; "speckle the wall with tiny yellow spots"
bespatter,
spatter dash a liquid upon or against; "The mother splashed the baby's face with water"
