Three-card monte.

(mathematics, engineering) A function or waveform that alternately ramps linearly upwards and then downwards.

plural of triangle wave

A contest between gun dogs / A practical test, especially one conducted in the wild

(medicine) An injury to the anterior cruciate ligament, medial collateral ligament, and medial meniscus.

A set of three behavioral characteristics — cruelty to animals, firesetting, and bedwetting past the age of five — claimed to be associated with later violent tendencies.

A plot device in traditional literature and theatre where a character begins sexual activity with someone else, then steals away after the lights are off, allowing another character to continue instead.

plural of bed trick

(idiomatic) A relationship involving three persons (usually two women and one man or two men and one woman) among whom there are conflicting and competing attachments of a romantic or emotional nature.

Third-person singular simple present indicative form of trick-or-treat