Crossword clues for Sleep letters 3 lettersAnswerClueREMSleep letters, or "Daysleeper" lettersREMSleep lettersREMDreamy sleep lettersREMDeep sleep lettersREMDream sleep lettersREMSleep-phase lettersREMSleep cycle lettersREMSleep lab lettersREMSleep stage lettersREMSleep study lettersZEELetter above a sleeping toonCLEARCONSCIENCEIt may help you sleep at night (notice the letter above letter 5)ZEESSleep letters?ZEESLetters symbolizing sleepCPAPMACHINEDevice keeping breathing going in people with sleep apnea (the second and fourth letters are the same, in case you get stuck)MURHYTHMSBrain waves, named for a letter, that are most active during sleepDREAMSleep phenomenon experienced in the second, third, and fifth letters of this answer