(gambling) A form of cheating at roulette in a casino by waiting for the ball to land on the winning number and then covertly placing chips on that number.

A man's formal hat, with a tall cylindrical crown (often of silk). / (construction) A kind of steel batten.

plural of top hat

Wearing a top hat.

plural of top-hat transform

(mathematics, signal processing) A particular operation that extracts small elements and details from images.

plural of top-hat pension

A scheme by which an employer offers top-hat pensions.

plural of top-hat plan

(US) An unfunded pension maintained by an employer primarily for the purpose of providing deferred compensation for a select group of management or highly compensated employees.