false start 
noun
1An invalid start to a race, usually due to a competitor beginning before the official signal has been given.It was not a ‘tragedy’ when he was disqualified for a false start in an Olympic trials race earlier this year, he said in mild rebuke of Prime Minister John Howard....
- Thorpe has been robbed of a chance to defend his 400m freestyle title in Athens after being disqualified for a false start.
- After three false starts, Ferrari was in bad shape; and Schumacher's abilities were being gleefully questioned.
1.1An unsuccessful attempt to begin something: she had finally found a job she liked, after various false starts...
- I've had a complicated history with jazz, with many false starts, disappointing attempts to divine the pantheon and forays into stuff I absolutely hated.
- In a way, I am glad the monsoon has finally begun after all the false starts caused by atmospheric depressions in the Arabian Sea end of May.
- Following several false starts in attempting to bring it back, the drama will finally be premiered in a webcast on BBCi in the spring.