mildewing

The five centuries he'd spent in that cave watching his Master mildewing hadn't really been very good to him.

It was impossible to dry your towel after bathing, or to press flowers without their mildewing.

Mercury, in proportions of around 200 parts per million, helped to prevent mildewing of surfaces and deterioration of paint in the can.

As it is, Lapa's charm exists in the gentle mildewing of its colonial-era architecture, in its sense of unfolding transformation.