An old Victorian term for a prostitute.
That expensive laced mutton gave me chlamydia.
Laced Mutton: define #2
A vain, ignorant, and superficial middle-aged woman who unsuccessfully attempts to make herself look youthful by caking on make-up and by wearing the trendy clothing of college-aged females. This phrase is actually an older popular characterization which one occasionally encounters in classic literature and especially in Golden Age British mysteries.
Check out that noxious old heifer — laced mutton of The First Water.