Definitions by jon feathercap

arcmyst 

when you have diarrhea after eating at a place called the "arc" in California

bro I had severe arcmyst last night from eating at the arc

arcmyst by jon feathercap November 2, 2022

Arcmyst 

Someone who obtained diarrhea after taking the COVID-19 vaccine or booster

uuuy bro, I'm having severe arcmyst after my covid booster

Arcmyst by jon feathercap November 2, 2022