Obsolete British insult: a toerag is a piece of cloth worn on the foot under the boot
to substitute a sock, especially in winter, and by vagrants. Something that
is squalid and disgusting; by extension, a bum, vagrant or tramp.
obscene (and thereby effective) insults such as tosser or wanker. It has fallen into disuse also
because it invokes an element of the old class system, snootishness
and looking down your nose at the lower classes.