The crossword question “Filth is GRIME” is a statement that is indicating that the word ‘grime‘ refers to dirt or filth. Grime is a noun that describes dirt that has accumulated on surfaces over time when it’s not cleaned properly. It might also refer to a greasy and grimy residue that forms on surfaces due to the lack of proper maintenance. This term is mostly used in reference to urban environments where pollution and dirt are common occurrences. In broader terms, this statement is indicating that the two words – ‘filth‘ and ‘grime‘ – are synonyms for each other. So, if someone says “the floor is covered in grime,” it means the same as “the floor is filthy“.