I wonder if that's from colonial usage, 'clart' is a Northern English/Scottish term for muck, attested since at least 1808: https://books.google.co.uk/books?id=

I wonder if that's from colonial usage, 'clart' is a Northern English/Scottish term for muck, attested since at least 1808: https://books.google.co.uk/books?id=UGAJAAAAQAAJ&printsec=frontcover&dq=etymological+dictionary+of+the+scottish+language+volume+1&hl=en&sa=X&ved=0ahUKEwjI5_27_t7MAhWjDsAKHZb7AJAQ6AEIHTAA#v=snippet&q=%22To%20Clart%22&f=false https://books.google.co.uk/books?id=UGAJAAAAQAAJ&printsec=fr... it's most commonly used as 'clarty' now here: http://www.scotsman.com/news/scottish-word-of-the-week-clarty-1-2994623 http://www.scotsman.com/news/scottish-word-of-the-week-clart... Jamieson's etymological dictionary suggests south germanic 'Kladd' as the origin of the Scots term.