sleeping with one eye open

Verb

sleep with one eye open (third-person singular simple present sleeps with one eye open, present participle sleeping with one eye open, simple past and past participle slept with one eye open)

1. (figuratively) To remain vigilant at all times, especially by remaining partially awake or sleeping only lightly so as to avoid being caught off guard.
   • Sleep with one eye open
     You have no idea what I'm capable of
     Keep claiming holier than thou
     My knife can stab more holes than you can count
     How dare you sleep where a king once slept
     And dry the tears of where his queen has wept2019, “Brimstone”, in Phil Bozeman (lyrics), The Valley (Deathcore), performed by Whitechapel