trilathon 

(1) a tripartite marathon, not to be confused with triathlon (a more or less grueling athletic competition featuring three athletic events and accompanying outfits) or, for that matter, biathlon (which combines two--often hilariously unrelated--athletic disciplines), neither of which has anything to do, at least etymologically, with a marathon (a long distance running event or anything that takes really long and tests the limits of human endurance--and boredom), after a Greek city by that name;
(2) the viewing of a trilogy, often a movie trilogy, in one sitting (with optional intermissions and other, more informal, interruptions);
(3) the viewing of the Lord of the Rings trilogy in one sitting.

Hey, wanna come over to for a LOTR trilathon this weekend?
I'm training for a trilathon next month.
A How to Train Your Dragon bilathon sounds like a great idea. Let's do it!

trilathon by mdsquared March 17, 2015