Sentence:  They have helped foster a corrosive, mean-spirited, angry and divisive atmosphere that May and her lieutenants are too weak to challenge. Into this <WSD>swill</WSD> comes Leave financier-in-chief, Arron Banks, who last week announced he was setting up a “Patriotic Alliance” to attempt to unseat 100 Remain-supporting MPs. 
Meaning of the word marked with <WSD> tags:  Anything disgusting or worthless.