The term “kowtow” refers to a specific type of bow which is used to express respect and deference, and also more generally to any sort of action which implies obeisance. The word and tradition comes from Imperial China, where people were required to bow to the Emperor or Empress of China. Today, people rarely kowtow to living individuals, although people may choose to do it in certain, very specific situations.
This word comes from the Mandarin kou tou, which means “to knock one's head,” and it entered English in the 1800s. To kowtow, someone kneels, and then bends his or her forehead to the floor. The posture is extremely submissive, leaving the back of the neck vulnerable, and it is therefore a mark of extreme respect and submission. In Imperial China, subjects were required to kowtow before approaching the emperor, and people also bowed to important officials, especially when they were asking for something.
Because China has become a more egalitarian society and there is no longer an Emperor, there are no situations in which modern Chinese (or anyone else) are required to kowtow to others. However, some people may choose to bow when asking for mercy, forgiveness, or a favor from someone else, and in some martial arts disciplines, people kowtow in certain situations.
Kowtowing is also practiced in some sects of Chinese Buddhism. In these sects, worshipers bow before approaching a statue of the Buddha, and they may also do so to Buddhist priests. Visitors to Buddhist shrines who are not Buddhist may also kowtow out of respect to Buddhist culture, if they are instructed to do so by a guide. Although bowing in this way is performed as a mark of religious veneration and respect, the act itself does not have religious overtones, contrary to some conceptions in the West.
Historically, the kowtow has had all sorts of implications. For example, representatives of foreign powers who bowed to the Emperor risked indicating that they, and their nations, were subjects of the Emperor. This became a problem for many foreign diplomats in China, as they did not want to bow, because they were official government representatives, and therefore they were not allowed in the presence of the Emperor.