Damp

Okay, ours isn't that bad but it was the first one on Google. 

Plus it's not necessarily actual damp I hate, it's the fact that we found damp behind our bed so we had to move the WHOLE bedroom around which was annoying and took ALL evening - all I wanted to do was go to bed and sleep but no I had to move all my clothes from rail to bed to rail (and watch them break in the meanwhile!)