1. To begin an activity or a movement; set out.
2. To have a beginning; commence. See synonyms at begin.
3. To move suddenly or involuntarily: started at the loud noise.
4. To come quickly into view, life, or activity; spring forth.
5. Sports. To be in the initial lineup of a game or race.
6. To protrude or bulge.
7. To become loosened or disengaged.

1. To commence; begin.
2. To set into motion, operation, or activity.
3. To introduce; originate.
4. Sports.
   1. To play in the initial lineup of (a game).
   2. To put (a player) into the initial lineup of a game.
   3. To enter (a participant) into a race or game.
5. To found; establish: start a business.
6. To tend in an early stage of development: start seedlings.
7. To rouse (game) from its hiding place or lair; flush.
8. To cause to become displaced or loosened.

1. 1. A beginning; a commencement.
   2. The beginning of a new construction project: an application for a building start.
2. A place or time of beginning.
3. Sports.
   1. A starting line for a race.
   2. A signal to begin a race.
   3. An instance of beginning a game or race: a pitcher who won his first five starts.
4. A startled reaction or movement.
5. A part that has become dislocated or loosened.
6. A position of advantage over others, as in a race or an endeavor; a lead.
7. An opportunity granted to pursue a career or course of action.

start something Informal.

1. To cause trouble.

1. At the beginning; initially.
2. In any case.

[Middle English sterten, to move or leap suddenly, from Old English *styrtan.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.