An older
slapper. Sometimes used to refer to the mother of a
slapper. An older woman, usually tartily or trashily made-up and/or dressed, who gives the impression of, or has the reputation for, being free with her sexual favours.
(Reference: Probably refers to the footwear favoured by older
people, particularly. Comment / interpretation: Perhaps she has hung up her highheels / white stilletoes and now goes for easy to wear, comfortable bedroom slippers? Thus, )