" . . . that Fleur girl tried this sort of charm, I think she was trying to put it into a trance - well, that kind of worked too, it went all sleepy, but then it snored, and this great jet of flame shot out, and her skirt caught fire - she put it out with a bit of water out of her wand."
-- Hermione about the First Triwizard Task (GF20)
Puts the target person into a deep sleep; subject is in a state almost like suspended animation and does not breathe for the duration of the spell.
Fleur tried to put her dragon into some sort of enchanted sleep during the first task (GF20). Dumbledore placed Cho, Ron, Hermione, and Gabrielle Delacour into this kind of sleep while they were “held hostage” by the merpeople in the lake (GF27).
References from the canon
"Dumbledore had put all the hostages into a bewitched sleep in Professor McGonagall's office, first assuring them that they would be quite safe, and would awake when they were back above the water" (GF27).