To pour forth from a narrow opening; to emerge from a narrow place like a defile into open country or a wider space.
A fortress at the end of a defile.
A narrow outlet from which a body of water pours.
to enter into another zone by way of accident or overcrowding; to overflow
(of a bad emotion, situation, etc.) to reach a climax
(of an infectious disease) to spread from one species of animal to another and particularly to humans