E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A woman of wealth, of station, or of rank. Verstegan says, It was
anciently written Hleafdian [? hlæfdige], contracted first into Lafdy, and then into Lady. Laf or Hláf (loaf) means food in general or bread in particular, and dig-ian or dug-an, to help, serve, or care for; whence lady means the bread-server. The lord (or loaf-ward) supplied the food, and the lady saw that it was properly served, for the ladies used to carve and distribute the food to the guests.
Another etymology is Hlàf-weardie and loafward ie, where ie stands for a female suffix like -ina -ine; as Carolus, female Carol-ina, or Carol-ine; Joseph, Joseph-ina or Joseph-ine; Czar, Czar-ina, etc. etc.
Ladies retire to the drawing-room after dinner, and leave the gentlemen behind. This custom was brought in by the Norsemen. The Vikings always dismissed all women from their drinking parties. (S. Bunbury.)