Wiktionary
cyclobarbital
n. A barbiturate derivative.
Wikipedia
Cyclobarbital
Cyclobarbital, also known as cyclobarbitol or cyclobarbitone, is a drug which is a barbiturate derivative. It is primarily available in fixed-dose combination with diazepam under the brand name Reladorm (100 mg cyclobarbital + 10 mg diazepam) and is used to treat insomnia in Russia.