When you have done nothing all day or are being lazy. It is to imply that your lack of movement, has caused mold or mildew to start growing on your body.
1. a man, formerly fastidious in dress and/or manner, who has now allowed himself to deteriorate with advancing age. 2. clothing that would only be worn by such an individual. (plural: mildewds)
* “Man, get a haircut. You’re such a mildewd.”
* “That shirt was mildewd 20 years ago.”
* “I don’t want to go to Shifty McNasty’s, it’s a bar for mildewds.”
* “The mildewd, no longer fashionably late, received a scowl from the prestigious crowd.”