A shortened version of the word madam, which was formally used when addressing women in the days when etiqute and common
curtesy were commonplace.
The term
Ma'am is often coupled with the word No, to create the phrase "
No Ma'am", which flows off the tounge very well if you have a Southern US accent.
Ma'am: Excuse me officer, could you tell me
the route to Texas, I seem to be lost?
Officer: Sorry Ma'am, that is something
I am unable to do at this time.