look up any word, like spook:
One absessed with appearing medium sized.

A mediumist will never take to anorexia, nor will he or she remotely consider gorging because not being fat is too much fun but food is just too delicious.
Colette is such a mediumist. Everytime we go jogging, she brings a sausage sandwich along for the trip
by Analogue July 29, 2005