n a fine woolly or pasty growth usually caused by damp and dirt, mould, mildew; fungus; (of teeth) tar tar; (of tongue etc.) a morbid or dirty coating; rust.
n a fine woolly or pasty growth usually caused by damp and dirt, mould, mildew; fungus; (of teeth) tar tar; (of tongue etc.) a morbid or dirty coating; rust.