Wiktionary
n. An amnesic condition characterized by insensibility to pain without loss of consciousness, induced by an injection of morphine and scopolamine, especially to relieve the pain of childbirth.
WordNet
n. a state of general anesthesia in which the person retains a slight degree of consciousness; can be induced by injection of scopolamine or morphine
Wikipedia
Twilight sleep ( English translation of the German word Dämmerschlaf) is an amnesic condition characterized by insensitivity to pain without loss of consciousness, induced by an injection of morphine and scopolamine, especially to relieve the pain of childbirth. This combination induces a semi- narcotic state which produces the experience of childbirth without pain, or without the memory of pain. The term 'Twilight Sleep' is also sometimes used to refer to modern intravenous sedation.
Usage examples of "twilight sleep".
This is usually done with a local anesthetic, but in this instance, while I don't think general anesthesia will be required, we'll probably want to sedate you that is, put you in a twilight sleep.
In fact, she had opened her eyes at last from a long twilight sleep and was, with this release, only now fully awake for the first time in years.