ˌfalse ˈstart noun [countable]

1. an unsuccessful attempt to begin a process or event:
After several false starts, the concert finally began.

2. a situation at the beginning of a race when one competitor starts too soon and the race has to start again

[TahlilGaran] Dictionary of Contemporary English ▲

a false start
a failed attempt to begin an activity or event.
After a false start when he left his first job after only a week, he was offered some modelling work.

[TahlilGaran] English Idioms Dictionary ▲