" . . . 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.
References from the canon