Three achievements in a single game, or similar, such as three consecutive wins.
Striking out three times in one game.
Three wickets taken by a bowler in three consecutive balls.
Three incidents or achievements that occur together.
A means of securing a seat in the House of Commons by placing one's hat upon it.
Three goals scored by one player in a game, in ice hockey usually followed by fans throwing their hats onto the rink.
Any magic trick performed with a hat.