Starter

One who, or that which, starts; as, a starter on a journey; the starter of a race.

A dog that rouses game.

a culture containing yeast or bacteria that is used to start the process of fermentation or souring in making butter or cheese or dough; "to make sourdough you need a starter"

an electric motor for starting an engine

food or drink to stimulate the appetite (usually served before a meal or as the first course)