Regurgitation is the process of a human or animal letting out the food it had been digesting. Sometimes, blood can come out as well.
Regurgitation can be very important to some animals, such as birds for example. It is used by a number of species to feed their young. This is especially when the young is in its nest or home and the parent hunts for food. Or some birds can occasionally regurgitate pellets of food that is not digestable, such as bones and feathers. Owls are known to do this.