1. A problem which makes a situation very difficult or too confusing: There is a major scheduling snafu with this airline tonight.
2. A mishap or mistake generally caused by incompetence and resulting in a delay or in confusion: Because the mail was not sorted correctly, there were several major snafus with the delivery of checks this month.
3. Etymology: Primarily a term used in the U.S.: "military slang, euphemistically, "Strictly Normal, All Fouled Up".

To cause a condition that becomes confused or which creates chaos: The improper identification of spending and receipts caused the tax declaration to be snafued for the tax preparer.

When David's secretary snafued the data for the financial report, it obviously resulted in a great deal of confusion; so, she was required to re-do it correctly.