1 definition by Rajbeer
A religion, such as Christianity, that is practiced every holy day, involving all Halo 3 Xbox Live subscribers. Holy Days are every night, from 6:00 PM-6:00 AM.
Person A: I celebrate Christianity, therefore my favorite day is December 25th.
Person B: Well I celebrate Halo Threetianity, and our holiday is September 25th.
Person B: Well I celebrate Halo Threetianity, and our holiday is September 25th.
by Rajbeer October 4, 2007