soporific

Etymology

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

noun

1. (pharmacology) Something inducing sleep, especially a drug.
   The doctor prescribed a soporific to help the patient sleep.
2. (figurative) Something boring or dull.

adj

1. (pharmacology) Tending to induce sleep.
   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! 1909, Beatrix Potter, The Tale of The Flopsy Bunnies
   I should imagine that the smooth riding and the quietness of the diesel or electric cab, coupled with the effect on the eyes of endless successions of sleepers disappearing from sight immediately under the driver's eyes, might in time have a soporific effect, so that the company of a second man, who can assist in signal observations when he is not at work in the engine cab, seems highly desirable in such conditions. 1961 July, Cecil J. Allen, “Locomotive Running Past and Present”, in Trains Illustrated, page 401
2. (figurative) Boring, dull.
   The professor delivered a soporific lecture.
   COP stands for conference of the parties under the UNFCCC, and the annual meetings have swung between fractious and soporific, interspersed with moments of high drama and the occasional triumph (the Paris agreement in 2015) and disaster (Copenhagen in 2009). 2019-12-02, Fiona Harvey, “Climate crisis: what is COP and can it save the world?”, in The Guardian