One's girlfriend, especially a lover with whom one lives.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "old lady" in a sentence
"The old lady and the crippled women cooed over William Henry as they left; he suffered their exclamations and pats with the same patience he used to give his dead mother, a side of him that fascinated George Parfrey."
"Came on horseback with a man in his forties—good-looking fellow, according to Mrs. Harris—an old lady who was here at the time."
"“And who does Little Miss Smarty Pants think would want to be friends with an evil old lady with a wooden leg, if I might ask?”"