Apparently it has a military origin (WWII Specifically) "1942, slang motto of Carlson's Raiders, (2nd Marine Raider Battalion, under Lt. Col. Evans Carlson, 1896-1947), U.S. guerrilla unit operating in the Pacific in World War II, from Chinese kung ho "work together, cooperate." Widely adopted in Amer.Eng. c.1959. "Borrowing an idea from China, Carlson frequently has what he calls 'kung-hou' meetings .... Problems are threshed out and orders explained." ["New York Times Magazine," Nov. 8, 1942]" Source: http://www.etymonline.com/index.php?l=g&p=13

"Gung-ho is a phrase borrowed from the Chinese language, frequently used in Chinese as an adjective meaning enthusiastic. The original Mandarin Chinese phrase is Gōnghé (工合), a standard abbreviation for gōngyè hézuòshè (工業合作社), meaning industrial worker's cooperative, first established in Baoji by Rewi Alley and his comrades and later spread to other parts of China during the World War II years. The phrase entered the American vernacular when it was picked up by then-Major Evans F. Carlson, USMC. According to Carlson, it was used as a slogan by the WW2-era Communist Party of China's 8th Route Army, led by Zhu De. The phrase was originally coined by Rewi Alley, a New Zealander who went to China in the 1920s and whose contribution to the country was later recognized when he became modern China's first honorary citizen. The industrial workers co-operatives that were formed as part of the Gung-ho movement stemmed from Helen Foster (Peg) Snow, wife of American journalist Edgar Snow. Peg Snow suggested to Rewi Alley that China needed widespread industry through the establishment of a movement (Alley, 1987). Carlson traveled with the 8th and with Rewi Alley. Later he used gung ho during his (unconventional) command of the 2nd Marine Raider Battalion. From there it spread throughout the U.S. Marine Corps (hence the association between the two) and into American society as a whole when the phrase became the title of an exciting 1943 war film about the 2nd Raider Battalion's raid on Makin Island in 1942 that emphasized savage combat to revenge Pearl Harbor. It is now often used in the ironic sense of excessively enthusiastic, overzealous." Source: http://en.wikipedia.org/wiki/Gung-Ho

Meaning - Zealous and eager. Origin: This is an adaptation of the Chinese kung - work, and ho - together. The Anglicized term gung ho became widely known in English as a slogan that was adopted in WWII by the United States Marines under General Evans Carlson. The New York Times Magazine reported this in 1942: "Borrowing an idea from China, Carlson frequently has what he calls 'kung-hou' meetings... Problems are threshed out and orders explained." The following year Life magazine reported: "He [Carlson] told them [the Marines] of the motto of the Chinese Co-operatives, Gung Ho. It means Work Together... My motto caught on and they began to call themselves the Gung Ho Battalion." The first record of gung ho in print was a little earlier. In October 1941, the Oakland Tribune reported a story about some captured short war films. This doesn't mention Carlson or the US Marines by name, but the films relate to their activities: "Other shorts are 'Information Please' and 'Gung Ho' with Regan McCrary." http://www.phrases.org.uk/meanings/167400.html NZer Rewi Alley set up an industrial co-operative movement in rural China in the 30s and 40s called Gung Ho. Somehow US troops in the Pacific theatre during WWII started using Gung Ho. If, or how the link between the two, can be established I don't know yet. Regards, Slán nui. Here's what The Cassell Dictionary of Slang, 1999 has to say: gung-ho adj. [1940s+] (orig. US) often of soldiers or sportsmen, enthusiastic, usu. aggressively so. [Chinese keng ho, awe-inspiring (lit. 'more fiery')]. The term was initially popularized as the motto of the US Marine Corps Second Raider Battalion, introduced there in 1942 by Lieut. Col. Evans F.Carlson] . gung-ho adv. [1940s+] enthusiastically, vigorously. [GUNG-HO adj.] When Marine Lieutenant Colonel Evans Fordyce Carlson went to China in 1942, he was impressed by the ardent spirit of the Chinese Communists. Trying to use their example to instill a sense of unity and purpose in his own troops, Carlson told the men in the Second Raider Battalion that _gung ho_ was the motto of the Chinese cooperatives and that it meant "work together." The Lieutenant Colonel was mistaken. Although _kung_ may be translated as "work" and _ho_ as "together," the two do not combine in Chinese to form a phrase meaning "work together." In fact, _kung-ho_ is simply the shortened form of the name of the Chinese Industrial Cooperatives Society. But the Marines didn't know that, and Carlson's men enthusiastically appropriated _gung ho_ to describe their own spirited group. Soon other marines also began to refer to the Second Raiders as _gung ho_, but they weren't calling them unified and hardworking. Instead, they were mocking Carlson's men as obnoxious, and _gung ho_ soon became a term of disparagement among marines. : From Merriam-Webster's Word for the Wise (November 10, 1997) at : http://www.m-w.com/mw/textonly/wftw/97nov/111097.htm The original name of the Chinese Industrial Cooperatives Society is: chung kuo kung yeh ho tso she, or zhong guo gong ye he zuo she. http://www.phrases.org.uk/bulletin_board/12/messages/266.html

Gung ho is a phrase used to mean "enthusiastic" or "dedicated". It is a transliterated version of the Chinese words Kung and Ho, which mean "work" and "together", but they do not form an offical phrase. The phrase entered the American vernacular when it was picked up by United States Marine Corps Major Evans Carlson. Carlson explained in a 1943 interview: "I was trying to build up the same sort of working spirit I had seen in China where all the soldiers dedicated themselves to one idea and worked together to put that idea over. I told the boys about it again and again. I told them of the motto of the Chinese Cooperatives, Gung Ho. It means Work Together-Work in Harmony...."

Eager