starter
noun
1.
an electric motor for starting an engine
2.
a contestant in a team sport who is in the game at the beginning
3.
the official who signals the beginning of a race or competition
4.
5.
6.
a hand tool consisting of a rotating shaft with parallel handle
7.
a culture containing yeast or bacteria that is used to start the process of fermentation or souring in making butter or cheese or dough