halo3sis 

the act of playing Halo3 while sleepwalking, or attempting to.

Dude, i woke up with my 360 controller in my hand AGAIN. i think i might have halo3sis.

halo3sis by Dylan Gerson November 6, 2007

halosis 

if you play to much halo you can get halosis

i played halo all night and forgot to brush my teeth so i got halosis.

halosis by mcpeepants4.5 May 4, 2008

halo2sis 

An oral problem amongst some Halo 2 fanatics.

Dude, I was so tired from playing H2 all night I forgot to brush my teeth before I went to bed. Again. I need some Listerine for this halo2sis or I’ll never get laid.

halo2sis by LegendaryBart July 28, 2006

halo3osis

its when u just got halo and noticed the the campaign is like a lil longer than gears so u go on online for like 5658 hours till you miss the school bus and realize that the game fuel taste terrible but ur just owing so much u basely just dident care and keep on playing till kidposin owns u and ur relived from ur trance.

guy 1: yo man i have terrible halo3osis and i missed school and that test.

guy 2: o man the test was easy but why did u decide to come in.

guy 1: one word kidposin

halo3osis by dominic sisti January 3, 2009

halosis 

When you are so distracted by playing halo that you forget to breate and/or blink.

I got halosis and almost suffocated.

halosis by Dylan S.! October 7, 2007