mud 
/ˈmʌd/ noun
/ˈmʌd/ noun [noncount] : soft, wet dirt
▪ He tracked mud into the house. ▪ His shoes were covered with mud. = His shoes were caked in/with mud. ▪ The car was stuck in the mud.
▪ He tracked mud into the house. ▪ His shoes were covered with mud. = His shoes were caked in/with mud. ▪ The car was stuck in the mud.
as clear as mud
informal : very difficult to understand : not clear at all
▪ The explanation was as clear as mud.
▪ The explanation was as clear as mud.
drag someone's name through the mud — see 1drag
sling/throw mud
chiefly US : to publicly say false or bad things about someone (such as a political opponent) in order to harm that person's reputation
▪ The candidates started slinging mud (at each other) early in the campaign. — see also mudslinging
▪ The candidates started slinging mud (at each other) early in the campaign. — see also mudslinging
your name is mud
informal ◊If your name is mud people do not like or trust you.
▪ The scandal ruined his reputation and now his name is mud.
▪ The scandal ruined his reputation and now his name is mud.
