able to fog a mirror
Alive, perhaps barely. (If one holds up a mirror to one's nose or mouth, the breath will cause fog to appear.) I spent the whole day moving furniture, so I'm barely able to fog a mirror now. He'll date any woman who's able to fog a mirror.
able to fog a mirror
Fig. Inf. alive, even if just barely. (Usually jocular. Alludes to the use of a small mirror placed under the nose to tell if a person is breathing or not. (Able to can be replaced with can.) Look, I don't need an athlete to do this job! Anybody able to fog a mirror will do fine!