Examples from the Web for water vapour
If gas is burnt in filtered air, intense fog is produced when water-vapour is introduced.
Water-vapour is not visible, though water (liquid) and ice can of course be seen.The Romance of Plant Life|G. F. Scott Elliot
This cooling made the dust-particles seize the water-vapour to form haze-particles of a larger size.
The friendly or water-vapour clouds are to be found several thousands of feet lower.Cavalry of the Clouds|Alan Bott
We cannot say if, or to what extent, these clouds consist of water-vapour.The Story of Evolution|Joseph McCabe