1
general::
Also, gung-ho. Extremely enthusiastic or dedicated, as in She was gung ho about her new job. This expression was introduced in 1942 as a training slogan for a U.S. Marine battalion, derived from what an American officer thought were Mandarin Chinese words for "work together." It was actually an abbreviation for the name of Chinese industrial cooperatives.
American Heritage Idioms
2
general::
Phrase(s): gung ho
Inf. enthusiastically in favor of something. • Bobby is really gung ho on his plan to start his own company.
McGrawhill's American Idioms And Phrasal Verbs