Lady

Lady was an aristocratic title. The male equivalent was "Lord".

Ladies
Ashildr used the alias Lady Sherade to marry the King of Samarkland. (PROSE: The Arabian Knightmare)

Lady Calcula was the mother of Davros. (AUDIO: Innocence)

Lady Jennifer Buckingham was a nurse and ambulance driver who served in the Women's Volunteer Reserve during World War I. She was abducted by the War Lords and hypnotised into participating in their simulated version of the war. (TV: The War Games)

Lady Madge Cranleigh was the mother of George and Charles Cranleigh. (TV: Black Orchid)

Lady Jane Grey was Queen of England for nine days between 10 and 19 July 1553. (TV: Lost in Time)

Lady Peinforte was a cavalier of Windsor in 1638, as well as a sorceress and poisoner. She threatened to reveal the Seventh Doctor's secrets if he would not give her the Nemesis bow. He refused and gave it to the Cyber-Leader. The Cyber-Leader expressed no interest in knowing the secrets Lady Peinforte offered to tell him, driving her mad. Just before the Nemesis prepared to lift off from Earth as the Doctor had programmed it, Lady Peinforte jumped onto the statue and merged with it. In space, the Nemesis exploded, destroying the entire Cyber-Fleet and Lady Peinforte as well. (TV: Silver Nemesis)

Lady Urton and her husband were possessed by the fire elemental in the late 19th century. (PROSE: The Burning)

Lady Elizabeth Hellcombe was the wife of Lord Hellcombe. She was killed by a Dalek in Hellcombe Hall in 1917. (COMIC: The Dalek Project)

Lady Louisa Pollard was Charley Pollard's mother. (AUDIO: Zagreus)

Lady Cassandra O'Brien.Δ17 considered herself to be the last "pure" human in the far future. She was among those who came to witness the destruction of Earth. (TV: The End of the World)

Lady Sylvia Thaw helped Richard Lazarus develop his rejuvenating device. She was also 's representative on the project. When Lazarus mutated after his rejuvenation went faulty, he drained the life out of her as he needed the energy for the mutation to stabilise. (TV: The Lazarus Experiment)

Lady Clemency Eddison fell in love with a Vespiform named Christopher in human guise in India in 1886. The relationship resulted in an out-of-wedlock pregnancy. (TV: The Unicorn and the Wasp)

Lady Christina de Souza was a minor British aristocrat and a thief. She was also a friend of the Tenth (TV: Planet of the Dead) and Eleventh Doctors. (COMIC: The Eye of Ashaya)

Other references
Beyond aristocracy, the word "lady" could be used to refer to any female. (TV: The Edge of Destruction et al.)

"Ladies and gentlemen" was a common salutation used in formal speeches and other public addresses. (TV: The Mind of Evil et al.)

Toilets and bathrooms reserved for the use of females were refered to simply as "the ladies". (TV: Boom Town)