yawner

A yawner is a term with several related senses in English. It can describe a person who yawns frequently; it can describe something that induces yawning; and informally it can refer to a dull event or activity that causes boredom.

Yawning is a motor act that involves a slow, deep inhalation, a wide opening of the mouth, and a long exhalation followed by a return to normal breathing. It is generally considered a reflex influenced by physiological and social factors.

Causes and contagion: Fatigue, boredom, low arousal, and sleepiness commonly trigger yawning. Some researchers propose brain-temperature regulation as a function of yawning, though this idea remains debated. Contagious yawning—yawning in response to seeing, hearing, or thinking about yawning—has been observed in humans and some social animals.

In everyday usage, "a yawner" can describe a dull lecture, film, or event; the term conveys tediousness rather than a clinical description.