|a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
In some sports, such as ice hockey, three goals by one player in a single game: “Lemieux scores for the third time tonight; he finally has the hat trick he's been looking for all season.”
Note: By extension, a hat trick is an outstanding performance by an individual, or a particularly clever or adroit maneuver: “She pulled off a hat trick with her presentation to the committee.”
Note: The phrase originally referred to a hat traditionally given to a cricket player who scored three wickets, or goals.
An extremely clever or adroit maneuver, as in It looked as though the party was going to achieve a hat trick in this election. The term originated in cricket, where it refers to three wickets taken by a bowler in three consecutive balls, traditionally rewarded with the presentation of a hat. It later was transferred to ice hockey, soccer, and baseball, where it denotes three consecutive successes (goals, hits), and then to more general use.