Lady Plural. Some nouns cannot be made into plurals just by adding an s es or changing f into a ves. In the meanings refined polite woman and woman of high social position the noun lady is the parallel of gentleman.
Woman female often used in a courteous reference show the lady to a seat or usually in the plural in address ladies and gentlemen. As the plural of Lady is Ladies. Compound noun Lady is an adjective here.
In regard to these alternative forms there are no strict rules to guide our use of them.
Lady of the house the female head of the household. A woman regarded as having the characteristics of a good family and high social position. In the meanings refined polite woman and woman of high social position the noun lady is the parallel of gentleman. The plural form is.