Answer:
As an English term, it generally is used to mean something like Work Together, or alternatively to show enthusiasm for the task. Someone who is Gung Ho is a zealot or a hard charger, without thought. It was brought into use in the Marine Corps during WWII by Evans F. Carlson of the Second Raider Battalion who had extensive China experience. The phrase itself is from the Mandarin language and refers to the workers cooperative. It is unlikely that Carlson even understood the Communist roots of the term, and only liked the sound, using it to motivate his small band of specialists.
Due to the manner in which US soldiers carried out their tasks,. Gung Ho has also become a way to describe actions taken in a jump in without thinking manner, eg too Gung Ho for my liking. Many British soldiers use the term Gung Ho for the shoot first ask questions later attitude of the American military. This meaning is more widely used in English speaking countries , rather than American English.