1 of 2


in·​som·​ni·​ac in-ˈsäm-nē-ˌak How to pronounce insomniac (audio)
: of, relating to, characterized by, or affected with insomnia
insomniac nights
insomniac tendencies
… he lived for several months with an older brother who didn't enforce bedtime rules. Joe started exchanging text messages with an insomniac friend and played online games against opponents on the other side of the planet.John Cline
The last thing my sisters and I would do on Christmas Eve—before retiring to our separate rooms and our private paroxysms of insomniac anticipation—was make sure our parents had put out cookies for Santa Claus.Christopher Caldwell


2 of 2


plural insomniacs
: a person affected with insomnia
Many insomniacs develop anxiety about going to bed and they fear sleeplessness, which can worsen insomnia.Andrew Weil

Examples of insomniac in a Sentence

Recent Examples on the Web
For the insomniac bedmate who turns on the light to read and wakes you up An eye mask can only do so much. Leslie Yazel,, 14 Dec. 2023 These narratives are magnetic forces that pull the reader into their worlds, leaving them eager to discover what comes next, from a bricklayer hiding his love for wearing red lipstick to an insomniac journalist fighting street violence. Roxsy Lin, Los Angeles Times, 13 Dec. 2023 Her concern for her single, insomniac brother is sincere, and at moments doesn’t quite skirt condescension. Sheri Linden, The Hollywood Reporter, 9 Oct. 2023 An insomniac detective investigates a man's mysterious death, and begins to fall in love with his wife while staking out her apartment. Jacob Linden, Redbook, 29 June 2023 Tall, healthy, and narrow-shouldered, the general looked like an insomniac bear driven out of his warm den by problems springing forth outside. Vladimir Sorokin, Harper's Magazine, 13 July 2022
Trump Has Promised to Do in a Second Term The misadventures that follow play like Inside Out for anxious insomniacs, as Orion rides shotgun while this gang of R.E.M.-cycle mavericks either lull folks into a restful state or aggressively knock them out . David Fear, Rolling Stone, 2 Feb. 2024 With a library of thousands and movies and shows, even insomniacs won’t run out of things to watch. Bellamy Richardson,, 6 Sep. 2023 Bears, instead, show little preference over morning or night, and dolphins are considered insomniacs who experience fragmented sleep. Sarah Wells, Popular Mechanics, 28 Aug. 2023 The show stars Antonia Thomas as Lisa and Craig Roberts as Danny, fellow insomniacs and friends who bond late at night. Mckinley Franklin, Variety, 9 Aug. 2023 There is, however, her insomniac’s attachment to a late-night radio show compassionately spotlighting anonymous confessions from the awake and troubled. Robert Abele, Los Angeles Times, 6 July 2023 Famous insomniacs: Franz Kafka, Arianna Huffington, Vincent Van Gogh, Bill Clinton, Marilyn Monroe, Abraham Lincoln, Madonna, Judy Garland, Groucho Marx, Margaret Thatcher and Tallulah Bankhead. Scott Lafee, San Diego Union-Tribune, 28 Mar. 2023 The sleep diary of an insomniac. Longreads, 18 Nov. 2022 Here’s a speculative short story collection ideal for streaming audiences accustomed to Black Mirror and The Haunting of Hill House: A runaway bride encounters a sea monster, a girl grows wings on her legs, and an insomniac is seduced by the Sandman. Mia Galuppo, The Hollywood Reporter, 24 Feb. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'insomniac.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History



from attributive use of insomniac entry 2


insomnia + -ac

First Known Use


1877, in the meaning defined above


1879, in the meaning defined above

Time Traveler
The first known use of insomniac was in 1877

Dictionary Entries Near insomniac

Cite this Entry

“Insomniac.” Dictionary, Merriam-Webster, Accessed 27 Feb. 2024.

Kids Definition


: a person who has insomnia

Medical Definition


1 of 2 noun
in·​som·​ni·​ac -nē-ˌak How to pronounce insomniac (audio)
: one affected with insomnia


2 of 2 adjective
: affected with insomnia
an insomniac patient

More from Merriam-Webster on insomniac

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!