from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Inducing or tending to induce sleep.
  • adj. Drowsy.
  • n. A drug or other substance that induces sleep; a hypnotic.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. Something inducing sleep, especially a drug.
  • n. Something boring or dull.
  • adj. Tending to induce sleep.
  • adj. boring, dull

from the GNU version of the Collaborative International Dictionary of English

  • adj. Causing sleep; tending to cause sleep; soporiferous.
  • n. A medicine, drug, plant, or other agent that has the quality of inducing sleep; a narcotic.

from The Century Dictionary and Cyclopedia

  • Tending to produce sleep.
  • n. Anything which causes sleep, as certain medicines.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. inducing mental lethargy
  • n. a drug that induces sleep
  • adj. sleep inducing


From French soporifique, from Latin sopor ("deep sleep"), from Proto-Indo-European *swepōr, from Proto-Indo-European *swep-. Unrelated to stupor (distinct in Proto-Indo-European). (Wiktionary)



Log in or sign up to get involved in the conversation. It's quick and easy.

  • The first pages, of most of these old papers, are as soporific as a bed of poppies.

    Nathaniel Hawthorne, Tales and Sketches

    November 23, 2011

  • Beddy bye-byes, bun-bun.

    March 30, 2009

  • Wait, eating lettuce makes you sleepy?

    March 30, 2009

  • Soporific means causing sleepiness. Something is soporific if it causes sleepiness. If the effect of something is sleepiness, that thing is soporific. It is not the effect of that thing that is soporific, it is the thing itself, which is a cause.

    Lettuce is soporific: the effect of eating lettuce is sleepiness. It is the cause of sleepiness--the lettuce--that is soporific, not the effect of that cause. It is possible that sleepiness is soporific (in that it tends to cause more sleepiness), but Beatrix Potter wanted to communicate the idea that lettuce itself causes sleepiness, not that sleepiness causes sleepiness.

    She apparently had a desire to introduce the word "soporific", but she did so inaptly. Instead of saying, "It is said that the effect of eating too much lettuce is soporific," she should have said, "It is said lettuce is soporific, that eating too much lettuce makes you sleepy."

    March 17, 2009

  • Beatrix Potter's use of soporific is also invoked in Margaret Edson's excellent play W;t. (Also a film, the clever typography is meant to come out as Wit.)

    March 31, 2008

  • I always bring out the Beatrix Potter quote as evidence that it is possible to nurture wordie-ness even in the very young. This is one of the very earliest books I remember reading. And even then I "got" what she was trying to do to my vocabulary, and I've been using the word ever since.

    March 31, 2008

  • 1. a. causing or tending to cause sleep. b. tending to dull awareness or alertness.
    2. of, relating to, or marked by sleepiness or lethargy

    December 11, 2007

  • "It is said that the effect of eating too much lettuce is 'soporific.'

    "I have never felt sleepy after eating lettuces; but then I am not a rabbit.

    "They certainly had a very soporific effect upon the Flopsy Bunnies!"
    -Beatrix Potter, The Tale of the Flopsy Bunnies.

    December 12, 2006