Synonyms for Foulness (same or very similar meaning)
WordNet sense 1 (a state characterized by foul or disgusting dirt and refuse):
filth, filthiness, nastiness
WordNet sense 2 ((of weather) the badness of the weather):
raininess
WordNet sense 3 (the attribute of having a strong offensive smell):
fetidness, rankness, malodorousness, stinkiness
From the ODE community, based on WordNet
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