Does English have a good expression – perhaps a phrasal verb with 'sleep' – to suggest that you forgot during your night's sleep?

Let's say you get a text message and you read it a moment before you fall asleep with the thought of answering the following day. But you completely forget. Your mind pushes it out of your head, it slips your mind.

Can you sleep it away? Or something like that?

  • Idiomatic sleep it off (not ...away) is used when we don't want the "pre-sleep" state to still apply when we wake up. So you can sleep it off if you're drunk, angry, depressed, etc. But we don't use that idiom for just forgetting (after a night's sleep). Maybe there's an expression that I can't call to mind just now. Jan 22, 2023 at 13:29
  • Frontiers uses 'sleep-dependent forgetting', but while there are corresponding hits on Google (including 'a sleep-dependent forgetting effect', 'sleep-dependent forgetting mechanisms'), I don't think there are enough to justify giving this term as an 'answer'. Jan 22, 2023 at 15:12
  • I sometimes hear "I've slept since then" but can't find much information on Google, so I'm sure how often it is used. "Do you remember what I was saying yesterday?" "Yesterday? Sorry but I've slept since then."
    – Kimbi
    Jan 23, 2023 at 2:20
  • 2
    There is no such word or phrase in common use. English does not have a word for everything.
    – Greybeard
    Feb 21, 2023 at 18:15

1 Answer 1


A scientific study of this exact phenomenon, that of forgetting things that happened just prior to falling asleep, was published in 1994. Titled "Sleep Onset Is Associated With Retrograde and Anterograde Amnesia," it concludes:

In general, if sleep is viewed as the event that led to the amnesia for the stimuli, as is the case under a consolidation theory, then one would consider retrograde amnesia to have taken place. However, if pre-sleep arousal level is viewed as the cause ofthe memory deficit, then anterograde amnesia would be said to have taken place. The results of this study lend support to a theory that poor encoding associated with the low presleep arousal level and sleep itselfled to the memory deficits. Under this explanation, both of the terms retrograde and anterograde are needed to accurately describe the phenomenon.

So the proper scientific terminology would apparently be the (retrograde and anterograde) amnesia associated with sleep onset. This isn't a single word, but it appears to be the best available term in the literature.

Presumably one could shorten this to sleep-onset-associated amnesia.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.