kiss

A kiss is a touch or press of one's lips against another person or object, often accompanied by movement of the mouth, and used to convey affection, greeting, consent, respect, or romantic interest. It may involve varying contact—from a light peck on the lips to prolonged, intimate lip-to-lip contact (often called a French kiss). Other forms include kissing the cheeks, forehead, or hands; air kisses are performed near the cheek without contact. The act exists in many cultures with differing social meanings and etiquette.

Etymology: The word kiss derives from Old English cysan, cossian, from Proto-Germanic *kussijan, related to German Kuss, Dutch kus, and similar terms in various languages, reflecting a long-standing human practice. The exact origins of the gesture are obscure and shaped by cultural norms.

Cultural significance: Across cultures, kissing can signal romantic love, familial affection, friendship, or political or social bonds. In some societies, public displays of affection are common, while in others they are restricted by custom or law. Literature and art frequently depict kissing as a moment of emotional turning points.

Biology and health: Kissing can trigger hormonal responses such as dopamine, oxytocin, and endorphins, reinforcing bonding between individuals. It also involves saliva exchange, which can transmit or acquire pathogens, so hygiene matters. Prolonged or vigorous kissing can cause lip or dental injuries, and people with contagious illnesses are typically advised to avoid intimate contact.