Learner's definition of LADY
a woman who behaves in a polite way
He bumped into some lady walking to the bus stop.
(chiefly US, informal) She's one feisty/sexy lady, I can tell you!
He helped a little old lady cross the street.
— used especially in polite speech or when speaking to a group of women
The lady behind the counter will take your order.
She told her little boy to say “thank you” to the nice lady for helping them.
Would someone please get the/this lady a chair?
Good evening, ladies and gentlemen!
Please step this way, ladies.
— sometimes used informally in U.S. English when speaking to one woman
Hey, lady, you forgot your purse! [=(more commonly and politely) excuse me, ma'am, you forgot your purse]
— sometimes used informally before another noun
◊ The phrase young lady is used in informal speech as a form of address for a girl or young woman. An angry parent speaking to a daughter, for example, might address her as young lady.
see also bag lady, cleaning lady, dragon lady, lady luck at 1luck
a woman of high social position
a man's girlfriend
chiefly British, old-fashioned
a man's wife
a woman who is a member of the nobility
— used as a title
it ain't over until/till the fat lady sings
— used to say that the final result of something (such as a sports contest) has not yet been decided and could still change