From Longman Dictionary of Contemporary Englishfast asleepfast asleepSLEEPsleeping very deeply Nick was lying on the sofa, fast asleep. → fast
Examples from the Corpus
fast asleep• Most of the household was still fast asleep.• Midnight approaches, and those not on duty are fast asleep.• She would have been fast asleep already, but for the Admiral's early-morning call.• She went back as she had come, fast asleep and docile, her face expressionless.• He had intended to visit Meryl, who was probably fast asleep by now.• Bless him, he was fast asleep on the sofa.• When her husband was fast asleep she must leave the bed, light the lamp, and get the knife.• He lay fast asleep, surrounded by flames and smoke.• The second time around, Stafford was fast asleep, wedged in between two large blond businessmen. 