The English word madam can mean
A polite form of address for a woman or lady.
(slang) A woman who runs a brothel, particularly one that specializes in finding prostitutes for rich and important clients.
These two meanings stand in great contrast. One is a civilized form of address, and the other connotes an uncivilized activity (i.e. prostitution).
Are there any Latin words with sharply contrasting meanings, like the contrast we see above?