Definitions of failing:

  • noun:   failure to reach a minimum required performance
    Example: "His failing the course led to his disqualification"
  • noun:   a flaw or weak point
    Example: "He was quick to point out his wife's failings"
  • adjective:   below acceptable in performance
    Example: "Received failing grades"
  • adjective:   unable to meet financial obligations
    Example: "A failing business venture"
  • name:  A surname (very rare: popularity rank in the U.S.: #30453)