a pill or capsule containing a drug for inducing sleep.
Origin of sleeping pill
First recorded in 1940–45
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for sleeping pill
a pill or tablet containing a sedative drug, such as a barbiturate, used to induce sleep
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012