My rule of thumb is that if you simply cannot find the proper word you are looking for, particularly in written correspondence, just go ahead and make one up. Human language is so sophisticated that the large majority of people will understand the meaning behind your fabricated word even though they have never heard it before. Whether the meaning is indirectly implied by virtue of the words around it, OR, the word simply "sounds right," most people will get it. It's frustrageous when they do not however... but there are worst things, like a kick in the scruttocks.