[syn: crank, starter]
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; 
- Example: "to make sourdough you need a starter"
The Collaborative International Dictionary of English v.0.48:
Self-starter \Self`-start"er\, n.
   A mechanism (usually one operated by electricity, compressed
   air, a spring, or an explosive gas), attached to an
   internal-combustion engine, as on an automobile, and used as
   a means of starting the engine without cranking it by hand;
   -- called also a starter.
   [Webster 1913 Suppl. +PJC]
The Collaborative International Dictionary of English v.0.48:
Starter \Start"er\ (st[aum]rt"[~e]r), n.
   1. One who, or that which, starts; as, a starter on a
      journey; the starter of a race.
      [1913 Webster]
   2. A dog that rouses game.
      [1913 Webster]
WordNet (r) 3.0 (2006):
starter
    n 1: an electric motor for starting an engine [syn: starter,
         starter motor, starting motor]
    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 [syn: starter, dispatcher]
    4: any new participant in some activity [syn: newcomer,
       fledgling, fledgeling, starter, neophyte, freshman,
       newbie, entrant]
    5: food or drink to stimulate the appetite (usually served
       before a meal or as the first course) [syn: appetizer,
       appetiser, starter]
    6: a hand tool consisting of a rotating shaft with parallel
       handle [syn: crank, starter]
    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; "to make sourdough you need a starter"