Is it true ? ........ The tank got its name because during its development during World War 1 it was considered a secret weapon and had to be referred to in letters as a 'Water tank.'
That would seem to make some sense to me, anyone else got anything more on this? The early tankers were brave men, they could and many did suffer serious injury while just traveling in the tank.
According to Wikipedia, yes, you are correct in your statement. The British came up with the name during their development.