From the root "Deo" (having to do with God, i.e. diety) and "Phobia": an exaggerated usually inexplicable and illogical fear of a particular object, class of objects, or situation.
A word created by John Cooper of the band Skillet, first used in the song "Savior" off of Skillet's 2003 CD, "Collide"
The irrational fear of being bald, more specifically the fear of letting people see that you are bald and the irrational belief that you can somehow camouflage the fact through a toupee, comb-over or some other method that people can discern from several miles away.