A kiss is the touch or pressing of one's lips against another person or an object. Cultural connotations of kissing vary widely. Depending on the culture and context, a kiss can express sentiments of love, passion, romance, sexual attraction, sexual activity, sexual arousal, affection, respect, greeting, friendship, peace and good luck, among many others. In some situations a kiss is a ritual, formal or symbolic gesture indicating devotion, respect, or sacrament. The word came from Old English cyssan (“to kiss”), in turn from coss (“a kiss”).
Kissing another person's lips has become a common expression of affection or warm greeting in many cultures worldwide. Yet in certain cultures, kissing was introduced only through European settlement, before which it was not a routine occurrence. Such cultures include certain indigenous peoples of Australia, the Tahitians, and many tribes in Africa.
A kiss can also be used to express feelings without an erotic element but can be nonetheless "far deeper and more lasting," writes Nyrop. He adds that such kisses can be expressive of love "in the widest and most comprehensive meaning of the word, bringing a message of loyal affection, gratitude, compassion, sympathy, intense joy, and profound sorrow.":79
The most common example is the "intense feeling which knits parents to their offspring," writes Nyrop, but adds that kisses of affection are not only common between parents and children, but also between other members of the same family, which can include those outside the immediate family circle, "everywhere where deep affection unites people.":82 The tradition is written of in the Bible, as when Orpah kissed her mother-in-law and when Moses went to meet his father-in-law, he "did obeisance, and kissed him; and they asked each other of their welfare; and they came into the tent" (Exodus 18:7); and when Jacob had wrestled with the Lord he met Esau, ran towards him, fell on his neck and kissed him. The family kiss was traditional with the Romans and kisses of affection are often mentioned by the early Greeks, as when Odysseus, on reaching his home, meets his faithful shepherds.:82–83
Affection can be a cause of kissing "in all ages in grave and solemn moments," notes Nyrop, "not only among those who love each other, but also as an expression of profound gratitude. When the Apostle Paul took leave of the elders of the congregation at Ephesus, "they all wept sore, and fell on Paul's neck and kissed him" (Acts 20:37). Kisses can also be exchanged between total strangers, as when there is a profound sympathy with or the warmest interest in another person.:85
Folk poetry has been the source of affectionate kisses where they sometimes played an important part, as when they had the power to cast off spells or to break bonds of witchcraft and sorcery, often restoring a man to his original shape. Nyrop notes the poetical stories of the "redeeming power of the kiss are to be found in the literature of many countries, especially, for example, in the Old French Arthurian romances (Lancelot, Guiglain, Tirant le blanc) in which the princess is changed by evil arts into a dreadful dragon, and can only resume her human shape in the case of a knight being brave enough to kiss her." In the reverse situation, in the tale of "Beauty and the Beast," a transformed prince then told the girl that he had been bewitched by a wicked fairy, and could not be recreated into a man unless a maid fell in love with him and kissed him, despite his ugliness.:95–96
A kiss of affection can also take place after death. In Genesis it is written that when Jacob was dead, "Joseph fell upon his father's face and wept upon him and kissed him." And it is told of Abu Bakr, Muhammad's first disciple, father-in-law, and successor, that, when the prophet was dead, he went into the latter's tent, uncovered his face, and kissed him. Nyrop writes that "the kiss is the last tender proof of love bestowed on one we have loved, and was believed, in ancient times, to follow mankind to the nether world.":97
Kissing on the lips can be a physical expression of affection or love between two people in which the sensations of touch, taste, and smell are involved. According to the psychologist Menachem Brayer, although many "mammals, birds, and insects exchange caresses" which appear to be kisses of affection, they are not kisses in the human sense.
Surveys indicate that kissing is the second most common form of physical intimacy among United States adolescents (after holding hands), and that about 85% of 15 to 16-year-old adolescents in the US have experienced it.