We have a tag called too_small, which isn't very informative at all. Wiki states it's for clothes too small for the wearer. How about aliasing it to undersized_clothes, to match the existing oversized_clothes?
Also I'd alias *_clothing to the above, as I just misremembered them as being spelt with "clothing" instead of "clothes".
It looks like a significant bulk of these images are simply micro_bikinis, which is much more populated. I'm guessing whoever did the tagging didn't realize that tag existed. Would there be any opposition if I switched them over to that?