Definition of "laudanum"

Ever since my recovery from the fever I had been in the custom of taking every night a small quantity of laudanum; for it was by means of this drug only that I was enabled to gain the rest necessary for the preservation of life.

1818, [Mary Shelley], chapter 4, in Frankenstein; or, The Modern Prometheus. […], volume III, London: […] [Macdonald and Son] for Lackington, Hughes, Harding, Mavor, & Jones

Whatever else was wanting to a wise man's happiness, —of laudanum I would have given him as much as he wished, and in a golden cup.

1821 September–October, [Thomas De Quincey], “[Part II.] Introduction to the Pains of Opium.”, in Confessions of an English Opium-Eater, 2nd edition, London: […] [J. Moyes] for Taylor and Hessey, […], published 1823, pages 129–130

Whipping and abuse are like laudanum; you have to double the dose as the sensibilities decline.

1851 June – 1852 April, Harriet Beecher Stowe, chapter XX, in Uncle Tom’s Cabin; or, Life among the Lowly, volumes (please specify |volume=I or II), Boston, Mass.: John P[unchard] Jewett & Company; Cleveland, Oh.: Jewett, Proctor & Worthington, published 20 March 1852

At the time, Wilson writes, England was “marinated in opium, which was taken for everything from upset stomachs to sore heads.” It was swallowed in the form of pills or dissolved in alcohol to make laudanum, the tincture preferred by De Quincey.

2016 October 16, Dan Chiasson, “The Man Who Invented the Drug Memoir”, in The New Yorker‎

In Sydenham’s 1683 treatise on the disease, for the sudden onset of violent symptoms he recommended laudanum — a tincture of opium and alcohol — to take the edge off the pain; […]

2020 November 13, Ligaya Mishan, “Once the Disease of Gluttonous Aristocrats, Gout Is Now Tormenting the Masses”, in The New York Times‎