Kung fu, also known as gongfu or gung fu, is a well-known Chinese term often used by speakers of the English language to refer to Chinese martial arts. Its original meaning is somewhat different, referring to one's expertise in any skill, not necessarily martial.
According to the legend of the Buddhist monk Bodhidharma, kung fu also has its origin in India. The Indian monk named Bodhidharma Sardili (also known as Da Mo in Chinese) traveled from India to China around 500 CE. It is said that he visited Shaolin monks in the Henan Province. While there, Bodhidharma awed the resident Chinese monks with his mastery of meditation. The secret was physical discipline which Bodhidharma saw lacking in the monks. He trained them in exercises designed to strengthen the body and thus their endurance. According to legend, Bodhidharma had attained such a level of control that he was able to bore a hole through a wall simply by staring at it for a number of years in meditation. These series of exercises the monks used evolved into what is known as kung fu. This is why Bodhidharma is credited with spreading Chan (Zen) Buddhism to China and for forming the modern kung fu.
The term kung fu was not popular until the 20th century, thus the word would be seldom found in any ancient texts. The term was first known to have been reported by a Westerner, French Jesuit missionary Jean Joseph Marie Amiot, in the 18th century and was known little in the mainstream English language until approximately the late 1960s when it became popular because of the Hong Kong films, especially those by Bruce Lee, and later "Kung Fu" the television series. Before that it was referred to primarily as "Chinese boxing". Today the most common use of the term kung fu is when referring to Chinese martial arts in general. Thus, when someone says they study kung fu, they likely mean they study one of the many styles of Chinese martial arts. The original meaning of kung fu is quite different, and is hard to translate as there is no English equivalent. In short, gong fu means "achievement through great effort" or simply virtue. It combines "gong" meaning achievement or merit, and "fu" which translates into man.
Originally, to practice kung fu did not just mean to practice Chinese martial arts. Instead, it referred to the process of one's training--the strengthening of the body and the mind, the learning and the perfection of one's skills. It referred to excellence achieved through long practice in any endeavor. You can say that a person's kung fu is good in cooking, or that someone has kung fu in calligraphy; saying that a person possesses kung fu in an area implies skill in that area, which they have worked hard to develop. Someone with "bad kung fu" simply has not put enough time and effort into training, or seems to lack the motivation to do so. Kung fu is also a name used for the elaborate Fujian tea ceremony (Kung-fu cha).
In Japanese, the characters for kung fu retain an approximation of their Chinese reading, and are pronounced "kanfu". Chinese martial arts in general are also referred to as "chugoku" or "chugoku kempo", which translates literally to "China fist" and "China fist law," respectively. (Kempo is a generic term for a punching/striking art of Chinese origins.)
While the term Kung Fu is used globally as a generic term for the Chinese martial arts — such as Shaolin Kung Fu — certain Chinese words may be used to denote some specific aspect of a style. These words are often based on the theme of the human hand. A common term is the Mandarin word "quan" or "chuan" (Cantonese: kuen, Japanese: ken), meaning fist, which conveys the sense of a style of boxing or striking, as in Shaolin Quan (Young Forest Fist) and Wing Chun Kuen (Eternal Spring Fist). The word "chuan", however, may not always denote boxing; Tai Chi Chuan (Supreme Ultimate Fist), for instance, contains the word "chuan" but does not focus on striking in common practice. Another example is the word "shou", or hand, as in Sanshou (Loose Hand or Free Hand).