Using of out like a light Hi! Could anyone tell me the meaning of the idiom "to be out like a light"? Of course I tried to find it by myself but I am not sure that I realize everything right. Some sources explain that this phrase means "to fall asleep quickly", e.g. I was out like a light when I got home after my hard work, other ones explain "to be in a deep sleep or unconscious", e.g. "I haven't heard any sounds around because I was out like a light". Just going to sleep and being already sleeping or unconscious are surely not the same. Dear native speakers, tell me which situations d'you use this phrase in? Give any instances please.