A Columbian is someone who attends Columbia University, or it's just the adjectival form of the word Columbia. For example, one might refer to the Columbian bureaucracy. In this case, it is a synonym for labyrinthine.
The Oxford English Dictionary (free from the campus network!) defines the etymology of Columbian and, by extension, Columbia, as:
f. mod.L. Columbia, poetical name for America (f. Columbus its discoverer) + -AN.
– OED Online