1. An event not occurring due to an unlucky circumstance outside original plan
2. Failure of a plan involving a third party.
3. When something or someone prevents something from happening through intervention.
2. A guy is in a bar flirting with a female, hoping to take her home and have sex with her. Another man comes along and starts flirting with her as well. He wins her over and she goes home with him instead. The guy looks down at his crotch and whispers, "foilage".
Or Man I got grounded. "Foilage"