n. 1. A beginning before someone; lead or advantage at the beginning. The other racers knew they couldn't catch Don if he got too big a head start. Joe has a head start. He began to study earlier than we did. 2. A good beginning. Let's get a head start in painting the house by getting up early. The teacher gave the class a head start on the exercise by telling them the answers to the first two problems.
Compare: RUNNING START.