The plural of madam is madams.
Madam is a term used to address or refer to a polite and respectful way to address or refer to a woman, especially one who is in a position of authority, such as a manager, a female proprietor, or the head of a household. It can also be used to address or refer to a woman who runs a brothel. In some contexts, Madam can be used to refer to a woman with great skill or expertise in a particular field.