"slut's wool"
Slut's wool, also known as dust bunnies
Public DomainSlut's wool, also known as dust bunnies

Slut's wool would more commonly be called "dust bunnies" these days: it is the collection of hair, dust and fluff that gathers in corners.  To the Victorians, "slut" primarily meant a woman of untidy or unclean habits, and only by extension a woman of loose sexual morals.