What does the word mildew mean?

Usage examples for mildew

  1. " We shan't mildew even if we ain't taken in for a considerable spell," Bill said contentedly, and added an instant later: " Now Seth's come I don't see why we should stand 'round here any longer." – An Amateur Fireman by James Otis
  2. The fumes of stale tobacco- smoke hovered in the air, and mingled most unpleasantly with those of the lamp above, and of the mildew that penetrated through the walls just below the roof. – El Dorado by Baroness Orczy